Not long ago, television viewers saw a distinguished looking gentleman peer out from their sets and ask imploringly, "Shouldn't you look at Grace?"

Chances are the pitch went right by most viewers, but the TV commercial for W.R. Grace & Co., the $6.5-billion conglomerate, was unique and revealing for at least a couple of reasons.

For one thing, it is rare for a major corporation to peddle its stock directly to the public, bypassing the Wall Street stock-marketing apparatus. But the technique also reflected the increasing frustration among Grace executives at the Street's apparent inability to get the Grace story across, which is why the company feels its stock price doesn't reflect its performance and potential.

Most exasperated of all is J. Peter Grace, the restless, mercurial, hard working and demanding chairman and chief executive officer of the company, which for 127 years has borne his family name but which is now decidedly his own creation. Grace showed his frustration in a quarterly report to stockholders last summer when he cited the company's declining stock price in the face of "superior results." He wrote: "There is, we believe, no reasonable explanation."

During a recent interview, Grace was characteristically blunt in talking about Wall Street analysts who have criticized his performance.

"I'd like to know how many of the critics have ever built a company from nothing to $350 million in earnings," he said. "If they sit around and write reports about what other people have done and done nothing else in life, then I say screw them."

What bothers analysts and frustrates Peter Grace is that the company's New York Stock Exchange-traded stock sits at about $45 a share, which is only about six times what the company earns per share. Analysts generally think that the company's stock should be at about twice its current price, especially considering that Grace is an industry leader in a number of its product lines, such as specialty chemicals, which alone account for $2 billion of the company's annual revenues.

One problem is that Grace cannot seem to shake its beginnings. Founded in 1854 in Peru by Peter's grandfather, William Russell Grace, the company has gained an almost indelible image created through nearly a half century of advertising of being simply an operator of steamships in South America and part owner of an airline, called Panagra, in that region. No matter that it has been out of both businesses--and of South America--for more than a decade; it is finding it downright impossible to expunge its Latin American ties from the public mind--which was another reason for the "You Should Know Grace" advertising campaign.

Of course, changing the company's name would quickly take care of that lingering confusion. But such a dramatic step is not going to happen now, considering Grace's immense ego, his strong sense of family, and his justifiable pride in tearing down, then rebuilding W.R. Grace so that it ranks No. 51 in the Fortune 500.

Like some other iron-willed chief executives such as Dr. Armand Hammer and Harold Geneen, Peter Grace--the longest reigning chief executive among those heading the Fortune 500 companies--has been able to dictate the company's destiny even though his family controls less than 5 percent of the common stock. (The biggest single shareholder, at 26 percent, is West Germany's Friedrich Flick Industrieverwaltung, a $4.5 billion industrial combine.) His annual compensation as chairman totals $750,000.

Under his direction, Grace has expanded through acquisitions and now has a staggering array of products and services under his name. These include retail outlets (Herman's Sporting Goods, Channel, Handy Dan, Angels, Diana, Sheplers), food chains (Del Taco, Coco's, Moonraker, Plankhouse, Houlihan's Old Place), coal, oil and natural gas (Booker Drilling, TRG, Homco & A-1 Bit & Tool, Davison cracking catalysts), construction (Zonolite insulation), graphic arts (Letterflex printing systems), chemicals (Dartak emulsion polymers, Evans sulfur compounds), agriculture (phosphate and nitrogen-based fertilizers), and hospital products (Vestal disinfectants).

According to company figures, Grace since 1952 has acquired more than 150 companies and sold off about 75 of them. But the architect of this patchwork acquisition policy says he'd rather not comment on the past. "I never counted them," he says of companies bought and sold. "It's bad to count your errors. Never complain, never explain, and never look back."

And while its been tough to disabuse the general public of its Latin American image, the company has found it even tougher to get some Wall Street analysts to take the company seriously because of what they view as Grace's unpredictability.

"Grace seemed to be buying anything in sight, and when it didn't work out, he'd spend a lot of time getting rid of it," says one critical analyst who asked that his name not be used. "The company is extremely difficult to figure out because of the myriad additions and subtractions."

But John Henry, of E.F. Hutton & Co. Inc., disagrees. "Analysts who think that Grace is complicated should look at the new Du Pont. That's unanalyzable," he says.

"Peter Grace has made a hell of a lot of acquisitions and made a lot of mistakes," continues Henry. "But that was in the late 1970s. Now he has it straightened out."

Grace himself allows that he "flip-flopped" in building the current corporate mix. For example, in the early 1960s when he was withdrawing the company from Latin America, he decided to make W.R. Grace into a petrochemical manufacturer. But, he says, "after pouring money into petrochemical plants" he "suddenly woke up" to the fact that the return on investment was only about 4 percent to 8 percent.

It was then that "we started to zig and zag," he says. "We tried everything because once we found that chemicals wasn't going to be that profitable, it was too late to get into electronics; so we blew it."

Typically, when Grace decided to change the course of his company he did it in a grand manner. In the early 1960s, for example, he plunged headlong into the grocery products business in Europe by acquiring a slew of companies dotted throughout the Common Market.

Then in 1969, when he got interested in fast foods, Grace bought whole chains of food outlets, so that now the company owns 600 restaurants, fast food operations and coffee shops.

That same year he turned to retailing, again in a big way. Among his acquisitions was Herman's Sporting Goods Store, then a New York retailer with three outlets, and "blew it up," in Grace's words, so that now there are 92 stores. Reportedly, it has the usual managerial problems that come with getting too big, too fast.

But the retail operations have been a drag on Grace's earnings and have drawn the company away from more profitable ventures.

Recently Grace had hoped to sell off one-half of its total retailing operation to a major European firm, Vroom & Dreesmann in the Netherlands. But the deal has fallen through.

In the early 1970s, Grace acquired a group of oil and gas producers. And while they did not pay off in the early days, they have since formed the basis for the company's broad-based energy holdings that now include coal. Says Grace, who clearly had high hopes of selling the company's troubled retailing operation to the Dutch and sinking the funds into energy development, "We have more opportunities in the energy business than we have capital to feed it."

Grace now contends that his restless casting about is long behind him. And to Wall Street critics who think otherwise, tough-talking Grace asks, "How much did we change our mix in the last three years, stupid?"

According to company estimates, the contribution to operating income breaks down as follows--52 percent from chemicals, 38 percent natural resources, and 10 percent consumer.

Although Grace once said he thought executives should retire by the age of 65, he is three years over the limit and shows no sign of calling it quits. Who his successor will be remains uncertain, as do the plans of the West German firm. The Flick firm, which manufactures chemicals, plastics, steel, paper and paperboard, controls three of the 31 seats on W.R. Grace's board of directors.

According to Grace, Friedrich Karl Flick is practically a member of the family. He got his early training at New York's Grace National Bank, once owned by W.R. Grace. And when Flick interests decided to invest in Grace the "ground rules were that they weren't going to take over control," says Grace, a man who takes the word "control" very seriously. CAPTION: Picture, J. Peter Grace heads a $6.5 billion conglomerate from his New York office. AP