According to my records, those were shows 336 - 340, taped on Monday, April 21, 1980. It was unusual for us to tape on a Monday. Emcee was Bill Cullen.
The show was pre-empted on Friday, 4/25/1980 (show #340) for an Iranian-hostage press conference.
Because of the pre-emption, we taped four shows, 351 - 354, on 5/12/80, also a Monday. Celebs were Susan Richardson and Bill Cullen, and Allen returned to the show after stringing us along for weeks with "I'm in the hospital but they don't know what's wrong with me". He later shared that the tabloids had been hounding him in the hospital, wanting to know if he had cancer (turns out he did). Up to that point, Betty didn't accompany him to the studio for every taping, but after his absence she came to every taping and did the driving.
Monday tapings were kind of fun because you might catch a glimpse of Johnny Carson who was taping TNT across the hall. However, it meant we couldn't go roaming around the backstage area of Johnny's set or read his monologue cue cards if they were left in place.
I wish I had saved all of that paperwork. I saved the ratings but would have to turn my place upside down to find them.