Only in New York could a football team that deserted the town for a larger playpen in the New Jersey swamps hold its "welcome home" luncheon Friday in mid-Manhattan. And only the Giants would walk out on the affair just as their highlight film was starting.

Still Giants in name but seldom giants on the field of late, the team opens the season against the Redskins today with 13 new players. Some of them, including ex-Steeler blocker Gordon Gravelle and reserve fullback Willie Spencer, are familiar and others, with starting quarterback Jerry Golsteyn being one, even veteran fans do not recognize out of uniform.

A decorator would label these Giants"late WFL," because John McVay and several players are refugees from the Memphis Southmen, although the fellow who rearranged Billy Kilmer's nose last season, Jack Gregory, insists:

"We've got more talent now than (any of the six years) since I've been here. Intelligence, size, speed, heart. This team's got it for the first time."

Even the most loyal Giant fan tends to forget a significant fact while remembering the team's 3-11 performance last year and the often dreadful shows this preseason. One of them in the luncheon audience of nearly 2,00, William Denis Fugazy, said he sits with Redskin owner Edward Bennet Williams each time the teams meet."I'll finally be able to cheer like hell if you guys upset them on Sunday," he said.

Gently, Frank Gifford reminded him, "we did beat Washington last year, you know." That was the infamous 12-9 game that included perhaps the worst performance by a winning quarterback-Norm Snead-in NFL history.

Indeed the Giants would seem the perfect opponent to open against if the Redskins did not have several large uncertainties of their own. Such as left cornerback and right lineback, Mike Thomas' leg and Kilmer's entire body.

The Giants exposed their most glaring weakness just this week by claiming two cornerbacks, Beasley Reece of Dallas and Ernie Jones of Seattle, off the cut list. All that after switching Ray Rhodes from wide receiver to cornerback.

Even now, Rhodes told John Jeansonne of Newsday, he is "hoping something will come up to get me back (to offense)."

That the Giants seemed to emphasize defense so heavily this year, until the addition of Gravelle, was somewhat surprising giben the fact that they surrendered just eight touchdowns in their finl seven games last season.

"If we have a really strong point," said McVay, it's the defensive line. And we've had some of the best practices this week since I've been here. I can feel the enthusiasm for Sunday."

To the Giants' most loyal customers, McVay pointed to his team and said: "these men will turn it around." He had a bit of history to remind anyone who considers Golsteyn a less-than-awsome quarterback choice.

"If you'll remember," he said, "the last time the Giants developed a young quarterback was '48 or '49. It was that fellow over ther (on the dais), Charlie Conerly." Of course, Giants fans would consider even Golsteyn's backups, rookies Joe Pisarcik and Randy Dean, superior to Snead and Craig Morton.

The return of fullback Larry Csonka to nearly full health after late season knee surgery is as significant as the early maturity of quarterback Golsteyn. Csonka's play, blocking as well as running, in the final exhibition was most encouraging.

"That gave me a good feeling," said Gregory. "Some doubted whether he could do it. We're good friends and I can say he might have doubted it. The greatest thing was playing th whole game against his old team (the Dolphins). He's one important thing."

Even though the Redskins have lost just once to the Giants in the 12 collisions since Allen became coach, the games have not always been as lopsided as might appear at first glance.

In Washington last season, Kilmer returned from Gregory's mauling to throw a five-yard touchdown pass to Thomas in the final 45 seconds for a 19-17 victory.

"And I remember the time they stole the ball out of Ron Johnson's hands (and won in New York). And one year we had them beat and Pete Athas was called for roughing or something," said Gregory.

"They play 60 minutes. That goes for the players and the coach. George Allen takes advantage of every second. They've got a mature team."

And one hoping for a positive performances from players expected to justify huge outlays in cash and draft choices long before now, John Riggins and Dave Butz, undoubtedly the most pleasant development of the preseason.

Last season was a bit of a transitional year for the Redskins. This year will be even more dramatic. No Larry Brown. No Jerry Smith. No Brig Owens. No Chris Hanburger for at least a few games and perhaps not Pat Fischer after his first several hard licks. The answers to preseason questions begin coming today.