SEEING DOUBLE:  Frank S. Rubinski, one of the 2,901 troops who arrived in Seattle yesterday aboard the Navy transport Gen. R. L. Howze broke into a wide grin when two Santa Clauses greeted him at the gangplank. The jolly Santas were Jack Gordon, left, and City Councilman Alfred Rochester. Earlier, Seattle's Civic Christmas Ship had serenaded with Christmas carols the troops as the big transport approached Seattle.