After seven months, the Reagan administration finally may be getting around to nominating a replacement for D.C.'s U.S. Attorney Charles F.C. Ruff.

In Maryland, J. Frederick Motz, of Baltimore's Venable, Baetjer and Howard has been picked for that state's slot. And the FBI is checking out Alexandria U.S. Magistrate Elsie L. Munsell, which would indicate the White House-Justice Department selection committee has made its choice for Virginia.

(While they're at it, the FBI reportedly is also conducting a background investigation of Fairfax County Judge James C. Cacheris for a Virginia federal court vacancy.)

But there's no action yet on the D.C. job, and the committee is hard-pressed to find an experienced 50-year-old superstar prosecutor who is willing to take the $52,000-a-year job -- meaning willing to live with an enormous pay cut -- and who's also a Republican.

Two candidates generally considered leading still fail to generate much enthusiasm among the selection committee members: Senate Rules Committee chief legal counsel Joseph E. diGenova and Paul L. Friedman, partner in the D.C. branch of Wall Street's White & Case.

Friedman, 37, styles himself an independent, spelled D-e-m-o-c-r-a-t at the White House. And diGenova, impeccably Republican, apparently lacks the experience that would suit the committee.

With those two dangling for months, and with several other candidates either rejected by the committee or turning down the job themselves, the committee began talking in early July to Donald Bucklin, partner in Wald, Harkrader & Ross and, like the other two, a former assistant U.S. attorney. Bucklin, 43, has the experience and claims to be a Republican.

Bucklin's problem is he can't prove his political purity. He hasn't been high-profile in politics, and he comes from Virginia, so he can't produce a party registration card.

Lawyers familiar with the process say it's conceivable other names might pop up. One informed source said there is still some sentiment on the committee that, barring an outcry against Ruff -- and there really hasn't been one -- maybe it would be best to let him stay in his job until his term expires in 1983. That's rather unlikely, however, that source said -- the inclination being, of course, to have the administration put its stamp on the office.

There appears to be a feeling among some members of the committee that time is running out, that for the sake of decency to those waiting, a decision should be made.

So the latest word sounds much like the word heard many times since the administration took office. A decision may be forthcoming in the next two weeks from the committee, chaired by White House counsel Fred Fielding and including Attorney General William French Smith, Associate Attorney General Rudy Giuliani, White House heavies James Baker and Edwin Meese and several other high level officials.

Other empty chairs: The White House is waiting to review later this week a list of three nominees by the city's Judicial Nomination Commission to fill the D.C. Superior Court vacancy created last month by the elevation of Judge James A. Belson to the D.C. Court of Appeals.

Despite the ruckus over Reagan's ill-advised attempt to bounce William A. Borders from his nominating commission seat, four years before his term expired, and to replace him with Philip Lacovara -- a plan shot down by a U.S. District Court judge -- the commission met on time to consider the vacancy. The commission has 30 days after a vacancy occurs on a D.C. court to send nominees' names to the White House.

The commission is expected to meet this week to select three names from a lengthy list of many previously considered names as well as more than a half dozen new ones, including Thomas Penfield Jackson, a prominent conservative and lawyer for former president Richard M. Nixon's 1972 re-election campaign finance committee, and former assistant U.S. Attorney Peter George.

The White House reportedly is not happy with the selections it has received from the commission in filling the four vacancies that have occurred so far this year. Many conservative lawyers believe that if the commission does not send at least one prominent conservative's name over, that will be read as a sign of confrontation with the White House.

Some personnel moves at the U.S. Attorney's office here. Gordon Rhea, deputy director of D.C. Superior Court operations, is moving over to executive assistant to U.S. Attorney Charles F.C. Ruff, replacing the post vacated by now Superior Court Judge Reggie Walton. Dennis Dutterer, deputy chief of the civil division, has been appointed general counsel to the Commodity Futures Trading Commission.

Fred Goldberg, general counsel for the D.C. Office of Consumer Affairs, is leaving to go into private practice ... Richard Rossier, formerly with the general counsel's office of the Council on Wage and Price Stability, and Ronald J. Marshall have joined Lambert, Griffin & McGovern.

Clinton W. Chapman, partner in Chapman, Norwind and Vaughters, recently took office as president of the Association of Plaintiffs' Trial Attorneys of Metropolitan Washington ... Andrew L. Sonner, Montgomery County state's attorney, has been elected vice president of the National District Attorneys Association ... M. King Hill Jr. of Baltimore has been elected president of the National Conference of Commissioners on Uniform State Laws. (That's the organization that drafts legislation designed to smooth conflicts in laws among the states.)

George B. Wolfe, formerly an associate with Wilmer, Cutler & Pickering, has become an associate with Moore & Foster ... David M. Thomas is joining the firm of William J. Skinner in Rockville, and Bruce Mackler and Edward J. Taggart are of counsel to the firm.

Gilbert E. Hardy and Jeffrey F. Liss, formerly associates at Wald, Harkrader & Ross, have become partners in that firm.

The 5-year-old Hispanic Bar Association of the District of Columbia recently elected its officers for next year. Charles Cervantes, of Venable, Baetjer, Howard & Civiletti was elected president. Carmen Citron of the FCC compliance bureau and Jose A. Toro of the U.S. Justice Department's land and natural resources division were elected vice presidents of the 140-member organization; Frances Herrera of the Antioch School of Law migrant paralegal project is recording secretary; Vilma Tirado of the Justice Department Civil Rights Division is membership secretary and Ray Velarde of the U.S. Department of Transportation's office of general counsel was elected treasurer.