The mustache is luxurious, the parrot is gloriously green, the gong is very loud and his politics, he says, are to the right of Louis XIV. It is clear that C.S. Taylor Burke Jr. cultivates his eccentricities the way gardeners tend their roses.

Burke is the president of the Burke & Herbert Bank and Trust of Alexandria, a light-stoned, high-ceilinged, barred-window affair at King and Fairfax streets where technology only reluctantly is embraced and the personal touch is carefully nurtured. Both approaches have proved very good for business.

The bank has been in the family for four generations, while the bank's computer - christened Isabelle - marked its first anniversary there this spring. For years, Burke had taken advertisements in the local paper, chortling over the fact that his bank had not foisted the anonymity of such a mechanism on its customers. Black crepe and purple ribbons festooned the door of the bank the day that era came to an end.

"I just knew we were going to lose some of our Old World charm when that thing came," said Burke, who took an ad a few years ago to apologize to bank customers when complaints from the big department stores forced him to start numbering the accounts.

Burke only resorted to Isabelle after he was finally convinced that the old Burroughs book-keeping machines he had relied on were no longer being made, spare parts were increasingly rare, and no one was being trained to repair them anymore.

In a world that often seems to have surrendered as Burke puts it, to "loud noise and sudden movement, such recalcitrance is much appreciated and many of his 10,000 customers respond to it with fierce loyalty.

"I just love this bank," said Isabelle Jasper, the computer's namescake and a regular customer at Burke & Herbert since 1952."Their way of doing business is very personalized. They know who I am there - everyone who works there is just set on knowing who you are. There's just no place like it," said Jasper, who is the wholesale coordinator for a local women's dress shop.

Jasper also prizes Burke for his willingness to lend money for housing renovation when Old Town's face lift was just beginning, his community involvement and the fact that while neighbors may change and property values rise. Taylor Burke remains - and remains the same.

The oil portraits of his ancestors glare down at him as he walks through the bank's lobby, constructed at a time when banks were built to look imposing rather than efficient.

Glaring at all who enter Taylor Burke's office is Runyon, who is the most audacious green a parrot can be and who is named after a friend of Burke's because he says, they have "similar personalities - they both like to bite people."

It is Runyon, Burke says with an attempt at a straight face, who reviews the bank's loan applications. "I find," he says of his parrot, "that he tends to be less revaged by human emotions."

And it is Runyon who is uttering high speed clucking noises one recent afternoon as Burke listens to the telephone tale of a woman in need of a loan. "Yes, ma'am," says Burke as he looks at his digital wristwatch. "Now tell me briefly. That's your own sole and separate estate, isn't it? . . . What do you mean, more or less? . . . Oh, well, just send me all the papers and I'll mess around with 'em . . . No I'll try not to lose them."

Taylor Burke displays his whimsies like the prizes of a cherished butterfly collection. He points proudly to the white buck shoes he is wearing as further evidence that he has foresaken society's mainstream for a dwelling place among its tidepools. He volunteers the fact that he uses the word "gramophone" for record player and "velocipede" for bicycle.

These proffered glints of personal eccentricity are imbedded in a life whose very consistency is somewhat stunning in these nomadic times and is, perhaps, the most eccentric thing about C.S. Taylor Burke Jr.

"I was born and raised to be a banker," he says. "I have always known just who I was and what I was going to be doing."

With so large a question settled so early in life, it is hardly surprising that Burke has ignored such modern pastimes as identity crises and learning how to be his own best friend. Instead, his idea of a good time includes dressing up as a gun-toting Arab surrounded by money bags and motor oil cans for an advertisement in the local newspaper. The ad was headlined "Sorry, Effendi, Our Bank is Not for Sale."

That, Taylor's first cousin told him was the worst thing he had done, since posing as the Mona Lisa (in another advertisement several years ago).

Since Taylor's cousin David is the executive vice-president of the bank, such remarks carry some weight, but Taylor has an explanation readily at hand.

"David," said his cousin "is the banker's banker. David is the straight one. Let's face it," says Taylor in satisfied summation, "David's kind of stuffy."

David Burke draws a different dichotomy. "I'm the sane one," he says. "And Taylor's the crazy one."

While David Burke "grins with embarrassment" at some of his cousin's more flamboyant stunts, he applauds his efforts to maintain a personnel touch as sound business sense.

"We play up the personalized approach a lot," says David Burke. "We lean over backwards to help our customers." He himself regularly drops by one elderly customer's house to pick up her deposits for her. "It's on my way home," he said. "And she does a lot of talking, tells all her friends. It can't help but be good for us."

The officers of other, larger banks agree "I have a great deal of admiration for Taylor Burke," said John W. Howard, a vice-president of United Virginia Bank. "That kind of service is a tremendous asset, there's no question." Howard feels that Burke's flamboyance is an asset in itself. "He's a good, smart businessman." Howard said. "He's showy all right, but he knows exactly what he's doing."

Whatever it is he's doing, it seems to be doing the trick. Burke says that the bank's profits have jumped from more than $439,00 in 1975 to $775,000 last year - a 75 percent increase that he characteristically attributes to "hard work and clean living."

Nevertheless, David Burke feels there will come a time when personalized service and exercises in nonconformity will become regrettably superfluous. Currently, the bank's assets among its five branches are about $60 million, but by the time they reach $150 million. David feels, "we just won't be able to give the personal touch. You grow, you lose control." he says. "We'll just have to begin to operate like most other banks."

Those are the banks that Taylor describes as the "22-story operations. You know how big a bank is by how high up the president's office is. I don't know what they do when they get up to the 22nd floor - talk to God, I guess."

Daird Burke Burke knows what he will do when Burke & Herbert outgrows its own idiosyneratic approach to the accumulation of capital.

"It won't be much fun, then." he said. "I guess well just go fishing."