While I was doing my semi-regular cleanout of my moderation queue to erase all traces of trollish behavior, I did notice one of the more persistent troublemakers made a comment I found rather interesting. I no longer have any vestige of the post, but to nutshell it, it was taking me to task because I "screwed up" the date that Price went to a full hour, claiming that the trial week ran from 27-31 October 1975 with the permanent change taking place the following Monday (3 November).
Every source I have on the subject, from the G-R FAQ (considered authoritative despite the dubiousness most people hold that message board in lately) to Wikipedia to the 2008 DVD set to my battered old Encyclopedia of TV Game Shows, lists 8 September 1975 as the first day of the "Super Anniversary Week" with the original Rainbow Wheel, temporarily knocking Gambit off the sked. 3 November is, however, the correct airdate for the permanent hourlong debut (including the Big Wheel we know and love today).
But for the life of me, I can't figure out where the October dates come from. All I can dig up is that it was the last full week of half-hour episodes (though occasional half-hour shows would continue to be produced through Season 22 as CBS time-filler), that Janice and Anitra both wore "HOUR POWER" shirts to promote the upcoming change, and that at least Bert Convy (host of Tattletales at the time) and Charles Nelson Reilly had cameos that week to "congratulate" Bob and the gang on their expanding timeslot.
Any guesses as to where this incorrect info may have originated, Price Nation?