I was in Romper Room in the 70's, how can I find archives that may be for sale from that show?

You might be out of luck...many local versions of Romper Room were never archived (the tapes were routinely erased and reused for other programs by the local stations that licensed the rights to produce the show in their cities). The two other answerers before me gave you two possible links to check out (either WGN in Chicago or The Museum of Broadcast Communications, which is basically the Chicagoland equivalent of the Museum of Television and Radio which may have tapes of the Chicago-area version of Romper Room in its archive).