Bill Warren in KEEP WATCHING THE SKIES always mentions original double-bills when he knows them and he doesn't mention one for FIRST MAN INTO SPACE. The only other s-f release he shows for February '59 is THE COSMIC MAN, for which he mentions a double-feature with HOUSE ON HAUNTED HILL "in Los Angeles at least." When FIRST MAN showed in my little neighborhood theatre in '60, '61, something like that, it played with two other movies. I don't remember what they were, but I do know they were neither s-f, nor horror.