Mike Henry, Rodney Howe and Bob Leach are planning to wear full evening dress (white ties, tails, top hats, carnations in their lapels) to the men's singles final of the Wimbledon tennis championships on Saturday.

And why not? They've earned the privilege of doing it up right. They were the first in line for the 500 Center Court tickets that will go on public sale at noon Saturday.

Thy started the line, a queue, as the British call it, at 10 a.m. last Saturday.By the time they get their tickets, they will have waited for seven days and two hours.

"They're mad, absolutely mad," said the policeman outside the gate of the All England Lawn Tennis and Croquet Club today, motioning at the queue of Saturday ticket-buyers, now 100 strong.

"We're very keen to see the final, and we've enjoyed the wait," said Henry, 22, a recent graduate in philosophy and psychology from Oxford University.

"We've managed to amuse ourselves most of the time, so we haven't been bored. A lot of people stop off and talk to us. I play the guitar. We brought along a lot of board games and cards, and we've got the dogs to walk and feed."

The dogs: an English sheepdog named De Selby and a 120-pound Irish wolfhound named Wilmot. They keep this dauntless trio from Surrey company.

These ultimate tennis lovers came to their Wimbledon vigil wellequipped with two cars, three cots, lawn tables and chairs and a suitcase per man full of clothes and all necessary papraphernalia for roughing it on the sidewalk outside the All England Club.

"One of us goes to a shop every morning for food, while the others hold his place in the queue," explained Henry. "We had a gas cooker, but the wolfhound stood on it and that was that. No more hot food. We've been subsisting mostly on fruit, cheese, bread . . . and lots of beer.

"Everything's gone our way except when John McEnroe lost. We had a lot of money on -- 1,000 pounds [$2,000], which we bet on him 10 months ago at 10-to-1. Now we are pulling for Roscoe Tanner to play Borg in the final. That would be a good game, and we've got 100 pounds on Tanner at 6-to-1."

Their dinner jackets hang neatly from a chain-link fence, and their starched collars and bow ties are ready in the suitcases for finals day.The only thing that worries Howe, 23, an accountant, is that he is supposed to be at work this week.

"I called up Monday and told my firm I was going to take a week off to queue for Wimbledon," he said today. "IM not sure they liked that."

At least if he is fired, "sacked," as the British say, he'll be wellprepared for waiting in the unemployment line.