The Soviet Embassy staff has been busy making the last repairs and embellishments on their glorious chancery-cum-residence (or were they just having the bug exterminators in?) in anticipation of this week's honored guests, Mikhail and Raisa Gorbachev. The beaux-arts edifice at 1125 16th St. NW (on Andrei Sakharov Plaza) is one of the last remaining grand mansions within walking distance of the White House.

But the Soviets haven't, thank goodness, had to send to Moscow for the gold leafers again.

In 1975 embassy administrative officers, curling their lips at the thought of capitalist artisans, sent to Moscow for gilders Victor Popkov and Vladimir Razumov to regild the work for the fourth time. The two spent some months laying the gold leaf on the mansion's magnificent pilasters and plaster ornaments on the piano nobile, the principal rooms on the second floor, until they gleamed like Rumpelstiltskin's gold.

In those rooms, Ronald and Nancy Reagan will be feted by the Soviets Wednesday night. The last presidential guest there was Richard Nixon, invited by Leonid Brezhnev when he visited during the Watergate hearings.

Soviet Embassy guests, usually stepping high on a red carpet, enter on the ground floor through a colonnaded reception hall in the Edwardian taste of this century's first decade. After guests have presented their invitations -- and likely their identifications, and perhaps even passed through a metal detector -- they ascend a sweeping staircase with an elaborate iron railing of gilded floral wreaths below a brass rail.

A smaller reception room upstairs might be used for more intimate introductions to the Soviet leader this week, though at former Soviet ambassador Anatoliy Dobrynin's farewell party, he received for some time on the stairway to the more private upper floors.

The grand salon is where most guests will congregate in the hopes of before-dinner vodka -- if Gorbachev relaxes his ban on the spirited drink. The salon is a mock atrium, or pavilion, with tall columns or pilasters alternating with French doors (heavily shuttered) on west, north and south. What remains is paneled or carved, often with floral motifs. The chandeliers, with their swags and drops, echo endlessly in the big mirrors facing each other over opposing fireplaces.

Ionic pilasters march down the heavily paneled dining room. Its marble mantelpiece is carved with the heads of a fierce-looking Tartar and flanking lions, topped with a tall mirror and flanked by sconces.

Hardly any American but Armand Hammer, philanthropist and peacenik extraordinaire, is likely to have seen the private quarters since Bob Hope infiltrated in the late 1960s when he went to the embassy to get his visa to go to Russia. But according to the architect's 1909 preliminary sketches (illustrated in the Fine Arts Commission's "Sixteenth Street" book) the second floor has suitable accommodations for Gorbachev: a very great bedroom with a bay of windows (probably all heavily shuttered like the rest of the windows).

The mansion comes complete with a history worthy of a Russian novel.

Washington cave dwellers sometimes still call the house "the Pullman mansion." Its builder, Hattie Sanger Pullman (widow of the Pullman Parlor Car millionaire, George M. Pullman), never lived there, but her children did use the lot for a tennis court before the excavation began. The matriarch built the house about 1909 for her son-in-law Frank O. Lowden, an Illinois congressman.

Hattie Pullman hired Nathan Wyeth, a Washington architect who later designed the president's Oval Office. For the Pullman mansion, Wyeth, educated at Paris' Ecole des Beaux Arts, used bits from a palazzo there, a country house here, an 18th-century French chateau balustrade there -- and the mansard roof popular in the Second Empire style. (Postmodernists of the '80s weren't the first to borrow ancient architectural details.)

A newspaper of the period claimed the house cost $361,477.64, of which the lighting fixtures accounted for $10,000 and the front doors $750. It was thought very modern for having a central vacuum cleaning system. All this glory was lost on the Lowdens, for Lowden didn't run for reelection in 1910. The house was sold to Natalie Harris Hammond, who resold it a few months later -- in November 1913 -- to the imperial Russian government, which bought the lot to the south the next year.

George Bakhmeteff, the last czarist ambassador, had married Marie Beale, a Washington millionaire who was famous as a hostess and diplomat. Her father, Gen. Edward F. Beale, once owned Decatur House on Lafayette Square. Marie Bakhmeteff needed a staff of 40, plus a French chef with 12 assistants, to run the 64-room house, according to Hope Ridings Miller's "Embassy Row."

Then, in 1917, came the Revolution. Bakhmeteff, some say, shipped the house's original antiques to his Paris home to save them from the Bolsheviks.

For several years, the house's remaining glories were sheeted and netted, and its status in limbo until 1933, when the United States recognized the Soviet government. When they took over the house, the Soviets hoped to exorcise the ghosts of czarist splendors by doing it up in the then current art moderne style, but the architect hired, Eugene Schoen, said he would not touch the "last hair of the last cupid."

So Wednesday night, Soviet comrades will entertain the American president in splendid salons where all that glitters is gold leaf and everyone -- we presume -- hopes the promises exchanged will be as good as gold.