February 26, 1981

-------------------------------------------------------------------- Jim Kemp is an editor and writer in the design field. By JIM KEMP THE next time you see a room of antique furniture look again. Those ''antiques'' may represent a growing phenomenon: copies of American furniture from museum collections. These museum-sponsored ''authentic reproductions'' offer historic American designs at relatively affordable prices.

IT wasn't until Lisa Cowen, a designer, had looked all over town for a new apartment that she decided to stay in the one she had lived in for ll years. ''I was separated and getting divorced,'' Mrs. Cowen explained, ''and I didn't want to live with anything that represented my past.'' But because her apartment was near her children's schools, she decided to change it, and instead of moving, make it work for her family's new needs. Mrs. Cowen hired Kevin Walz, an interior designer, to undertake the project. The renovation was based on a complete redesign of her living space - to make the relatively small rooms double as entertaining and play spaces. Construction costs came to $62,000, not including furniture, lighting fixtures, carpeting and the slate floor.

Reagan faces decisions on policy in Southeast Asia A2 At least 16 killed in crash of U.S. Navy plane off Philippines A2 Study group sees need for greater European military effort A3 Greek quake kills 15 and seriously wounds 53 A3 Pope gets a warm welcome in Nagasaki A4 Queen Mother and Lady Diana have a tete-a-tete A5 Brezhnev aide denies Soviet arms go to Salvadoran rebels A8 Around the World A9 Group plans to protest disappearance of Guatemalan A13 Government/Politics Judge refuses to dismiss suit over F.B.I. informer A14 Wisconsin Democrats and Republicans upset by Court's move A17 Koch attacks group that criticized his anticrime proposals B11 Democrats demand more details on budget B15 General Around the Nation A14 Art Deco buildings at center of Miami Beach conflict A14 Well Fargo discloses details of bank fraud A15 Concern growing over Nassau's overcrowded jail B7 Consumer prices rise 0.8 percent in New York region B12 Chicago financier charged with fraud in search for Peking Man B16 Education/Welfare Ex-Congressman confident as new head of N.Y.U. B8 Features/Notes Notes on People B6 Man in the News: John Brademas, new N.Y.U. president B8 Obituaries Deszo Ernster, bass at the Met B16 The Home Section Home Cloning antiques: Museum reproductions C1 Restructuring an apartment to provide flexible living for three C1 Removing graffiti outside the house C3 Repairing damage to your garden C9 Bonsai lessons for the terrace C11 Home schooling, an issue for parents C1 Hers C2 Helpful Hardware C2 Home Beat C3 Home Improvement C4 F.D.A. is urged to limit salt in processed foods C5 Armani's new men's line adds casual and military elements C8 Design Notebook C10 Arts/Entertainment Nana Mouskouri, Greek pop singer, gives recital C12 Grammy awards presented at Radio City C13 City rejects Christo's "Gates" project for Central Park C15 Great social agonies are still attracting composers C16 First novels get record prices, but average advances decline C16 New-music concert by the American Composers Orchestra C16 "The Freak," a staging of the life of Edgar Cayce, mystic C17 Patrick Anderson's study of marijuana politics is reviewed C18 Judith Somogi named "first conductor" of Frankfurt Opera C18 Disney shows to appear on CBS in 1981-82 season C20 Sports Dave Anderson on John Ziegler's hockey law D20 Baruch and City College gain in tourney D20 Coghlan to skip mile and go for three-mile record D20 Baseball strike set for May 29 if no accord is reached D21 Rangers triumph over Sabres, 6-3 D21 B17 Bullets turn back Knicks, 120-105 D21 Flames rout Islanders, 11-4 D21 Seton Hall beats St. John's, 70-63 D22 News Analysis Bernard Gwertzman on Washington's El Salvador moves A6 Serge Schmemann views dispute on Rosedale school annex B1 Aljean Harmetz on the losers in Hollywood's poker game C15 Editorials/Letters/Op-Ed Editorials A18 Why only a popgun tax cut? Where allies can meet A primary's not a free-for-all Topics: diversions Letters A18 William Safire: the savings of El Salvador A19 Anthony Lewis: a tax-and-spend- ing cut of pie in the sky? A19 Jorge I. Dominguez: on Cuban- United States ties A19 Richard Scobey: the Peace Corps, at heart A19

''It is entirely appropriate to dispatch noncombat advisers to tell those people how to defend themselves against Cuba.'' - Howard H. Baker, Senate Majority Leader, on El Salvador. (A1:2.)

The Atlantic Richfield Company, the country's seventh-biggest oil concern, announced yesterday that it had agreed to sell The Observer, Britain's oldest Sunday newspaper, to the George Outram Company, a Glasgow publishing subsidiary of Lonrho Ltd., the British mining conglomerate, in a stock exchange valued at $14 million. The announcement represents the second recent ownership change on the troubled London newspaper scene, following Rupert Murdoch's purchase of The Times of London and its affiliated publications from the Thomson Organization. The Sunday Times is The Observer's chief rival.