As the hum of sliding doors fills in for the national anthem and the faces of Baseball Hall-of-Famers smile from pocket-size bubble-gum cards, the two great bubblegum card manufacturers in the nation step up to bat against each other.

The year: 1962.

The place: the Federal Trade Commission.

Now the Washington National Records Center in Suitland is cataloguing the suit in a display called "The All-American Sport: Baseball as Business." It's the pilot adventure in a program designed by the National Archives to teach young archivists and designers professional exhibiting.

In the case, an FTC examiner and a second-string baseball bubble-gum card producer, Fleer Chewing Gum Company took on Topps Chewing Gum Company. Both claimed that Topps was acting in restraint of trade. Topps was cleared, but it's going into extra innings in Philadelphia now, in another antitrust suit between Topps and Fleer.

In the exhibit, against a backdrop of green picket fences and pin-striped cloth, the 1962 federal documents are spread around the hall so viewers can follow the case from the original Fleer claim to the decision.

Sprinkled among the documents are such faces as Mickey Mantle, Honus Wagner Babe Ruth, Maury Wills, brooks Robinson and Ted Williams -- on the baseball cards, coins and buttons used as evidence.

There's also a Topps contract signed by Don Drysdale's father, agreeing that the then-minor would allow his picture and signature to appear only on Topps' cards.

The Archives' training program requires interested archivists to spend six weeks of formal training in exhibiting. It was after this that two archivists at Suitland, John Veron and Richard Wood, admitted "sport nuts," struck on the baseball card dispute as their entry into the program. Veron said the idea came from a fellow archivist researching the case.

After several innings of contemplation, Wood, Vernon and designer Guy Schum produced a colorful exhibit of documents, bubble-gum, cereal and Jello baseball cards against a background of blown-up black-and-white pictures of baseball stars blowing realistically pink bubbles of gum.

Wood and Vernon say the Suitland exhibit was the "Maiden voyage" of the program in the nation; future exhibits will be on the deaf and on blacks in war. The baseball card exhibit closes October 31, but it's so successful, says Archives curators Caryl Marsh, that it'll be moved to the Archives downtown in time for next season's spring training. CAPTION: Pictures 1 and 2, no caption