I'm curious, because I've never been enough of a fan to track them all down: What celebrity episodes are known to exist?
Here's what I've got (I think I've got everything that's currently in the trade curcuit):
--May, 1979 - very excitable woman wins $25,000 (joined in progress) (OC)
--June 1, 1979 - Howard Wilson's first show (OC)
--June 4, 1979 - Howard's second (OC)
--June 6, 1979 - Howard's fourth (OC)
--June 8, 1979 - Howard's fifth (pre-empted on the 7th for CBS "Magazine") (OC)
--June 11, 1979 - Howard's sixth (OC)
--June 12, 1979 - Howard wins $25,000 (Guantlet run only) (OB)
--Aug 27, 1979 - Randy Amasia's first ep. (SM)
--Aug 28, 1979 - Randy's Guantlet win (SM)
--late Oct, 1979 - Tami vs Steven (halfs of two eps.) (SM)
--Apr 8, 1980 - Trish Stewart, Jamie Farr (OB)
--Apr 9, 1980 - next show; last segment is missing (OB)
--May 20, 1980 - Gary Collins, Mary Ann Mobley (credits clipped) (OC)
--May 21, 1980 - Gary and Mary Ann (no closing credits)(OC)
--May 22, 1980 - Robert Vaughn, Marcia Wallace (no closing credits) (OB)
--May 23, 1980 - David Jones wins $25,000 (no closing credits) (OB)
--May 29, 1980 - John Saxon, Betty White (rough video) (OB)
--May 30, 1980 - (last ep.) John and Betty (rough video) (SM)