ACCORDING TO the joke, the sure best-selling book of all time would be the one about Abraham Lincoln's Doctor's Dog's Sex Life.

Oakwood, a great 18th-century equestrian estate in Fauquier County, Va., has all those plots a plenty.

The house belonged to the family of Lincoln's private physician, Dr. Robert King Stone, whose wife was related to the house's original builder. It is said the connection saved the house from burning during the War Between the States.

A later owner bred dogs. So there's your best seller.

With all this and more going for it, it's not surprising that Sotheby Parke Bernet International Realty Corp., which likes promotable property, has chosen Oakwood for its first double auction.

On Sept. 21, Edward Lee Cave, chairman of the realty company and a Virginian-born who always uses his middle name when he comes home, will auction off both Oakwood and its contents. The real estate will be offered either as a whole or in four parcels.

This will be the first time Sotheby has auctioned off real estate, though its house auctions (the Garbisch auction on the Eastern Shore is the most recent locally) are famous for disposing of the insides of houses. Two or three high-price house auctions have been held in this area recently in this time of slow house sales. The procedure is quite common in Europe.

Cave expects to get somewhere in the neighborhood of the asking price, $1,770,000, for the real estate: a 21-room 18th-century stone house, 435.2 acres, a 36-stall stable, two hay barns, a horse breeding barn, storage barns, a stone spring house, a six-car garage, and three seven-room tenant houses.

The county is full of famous houses and grand estates, including that of Paul Mellon. Oakwood is, of course, not the only million-dollar-plus house in the area on the market.

Charles Seilheimer, president of Sotheby's realty, counts 11 other houses in the Virginia hunt country with an asking price of over a million dollars. The most expensive on his list is Kinloch, 4,200 acres on the Rappahanock River, on Route 17 south of Port Royal. The estate, owned by Lee D. Butler, the Lincoln Mercury dealer, who has given part of it to Princeton, is up for sale for just under $7 million dollars.

The auction sale of the property points up the current difficulties of selling big expensive estates in these times of high interest. "The foreign money which was buying big estates here," said Seilheimer, "has been sitting in those 18-percent-interest money market funds, waiting for house owners to get hungry."

George Szego, a solar energy pioneer, has owned the house since 1972.

"He's not one to sit around and wait for things to happen," Seilheimer said. "So he said, let's go ahead with the auction. We'd thought of a real estate auction for sometime, we were just waiting for the right one to come along. We've had a lot of interest in the estate, but we needed some event to make the prospective buyers take action."

The house has had a racy history.

Szego says the Prince of Wales and Wallis Simpson courted at Oakwood. "Mrs. Simpson was a great friend of Madge Stokes Stone Larrabee, then the owner of the house. They came back to visit Oakwood as the Duke and Duchess of Windsor in 1941. We still call the southwest bedroom the Prince of See FORM, Page 2, Col. 1 FORM, From Page 1 Wales Room. He wasn't the only one to sleep in the big bed. Edgar Allan Poe and Lincoln both slept there, and maybe General Lafayette."

Mrs. Simpson, according to Szego, lived in Fauquier County while awaiting a divorce."She's supposed to have said: 'It's the sunniest place for the shadiest people.'"

Oakwood was once part of a huge 18th-century land grant, signed by Lighthorse Harry Lee, given to Col. Martin Pickett for his services in the American Revolution. Colonel Pickett was a founder of Fauquier County. He gave the original house and 1,500 acres of land as a wedding gift to his daughter.

The house sits at the top of View Tree Mountain, sheltered by ancient oaks, magnolias, dogwoods and one of the oldest hollies in the county. The house is set amid old gardens, including a boxwood walk with flagstone cut around a dinosaur footprint, a fountain, gate, the original water pump, garden statues, fishpond, a small stream, a playhouse, a springhouse and even a pet cemetery. The original stone "patent" house was built sometime between 1700 and 1735. A patent house is one built to take occupancy of a land grant (called a patent).

The original 16-by-17-foot keeping room, now the den, is still the pleasantest in the house, with smoky exposed beams and ceiling, white washed stone walls, a huge fireplace and a big slate floor. The two-foot thick walls are pierced by a door which gives the den its private entrance to the outside, the better for assignations.

To this was added a formal 16-by-32-foot dining room and fireplace in 1790. In 1803, a pretentious yellow stucco Georgian house was added to the front of the old stone house. The house now has eight bedrooms and six baths. The Szegos needed them all. They have nine children, all but one adopted. "We have three Americans, two Vietnamese, two Mexicans and two Canandian Algonquin Indians," he said. The children now are mostly grown.

The 40-by-20-foot living room is 14 feet high with two fireplaces. On one wall is a huge pine hutch (10 feet long, 7 feet high). Lincoln gave the hutch to Dr. Stone for his services. Stone must have appreciated it. Szego says the night when Lincoln was shot, "Dr. Stone, in a one-horse chaise, dashed up to the house where they'd taken Lincoln at such a rush that his horse keeled over dead."

The clock and candlestick mantel garniture was given, according to Szego, to the house's owner by General Lafayette, who'd come to the country to buy farm machinery, and was widely feted. A firescreen in the upstairs bedroom is said to have been the inspiration for the horse Andrew Jackson is riding in the Clark Mills statue in Lafayette Square. The Knable piano is dated 1894.

Szego bought many of the furnishings from the previous owner, Mrs. Larrabee. "Our house in California had burned down," Szego said, "after we'd sold it but not closed on it. All our furniture and clothes were burned, so we were glad to buy some things."

The unusual 14-by-40-foot corridor hall has three entrances, each with an impressive eight-panel door. Leading off the hall is a 14-by-17-foot study and a similar sized library.

In the back of the house is a family dining room (14 by 17 feet), a laundry room, and a pantry freezer room with a lockable food pantry (6 by 11 feet).

Szego said the attic rooms have bars on them. "During one period, when the owners of the estate were afraid of slave uprisings, the slaves were locked in the attic at night."

Szego -- whose company, Intertechnology was one of the first of the solar energy firms -- built the 25-by-50-foot solar heated swimming pool with 10 collectors. He also laid down the tennis court with an innovative cross fiber surface. It has an adjacent spectators' gallery adjacent. He also built the 11-acre lake, named for Colonel Pickett.

In 1922, the first Gold Cup Steeplechase was held at Oakwood. After Szego bought the property, he bred race horses. The great stable has an eighth of a mile indoor track. "You can't blow out a horse on it, but it's great if you want to show what a horse can do and it's raining."

Szego is currently serving as consultant on a project to heat the Naval Academy with solar collectors. "We believe some developing countries are also interested in our help. Intertechnology expanded under a president who believed in solar heat, but we've had to contract under this president who doesn't believe in it."

A personal tragedy has also made it difficult for Szego to keep the house. His wife was seriously injured in an automobile accident a few years ago.

"I enjoyed having the house," he said, as he walks around the property which gives a 360-degree view at its highest point, View Tree Mountain. "You always have to be grateful for such experiences. But she's like a beautiful mistress who always wants a new diamond bracelet. Oakwood always wants one more."