Okay so I was looking for info on Fullerton’s grand opening, and weirdly this for hire listing from April of 1980 lists Fullerton as upcoming, which is after the Wiki’s & Every Location List’s March 1980 listing. https://www.newspapers.com/article/the-los-angeles-times-la-area-manager-wa/192692185/
https://www.newspapers.com/article/the-los-angeles-times-ptt-la-area-advert/192694142/
This article from July lists 9 California locations, which #9 maybe being Fullerton. It could also be from earlier and just reused (Either way, Fullerton isn’t open in March.
This from the May 1980 Pizza Times is probably where the date is from, but nothing suggests the tours having been going on AT Fullerton as it’s under HUNTINGTON’s section and the Fullerton grand opening is only mentioned.
Not to mention PTT’s plans on generally opening about 2 stores in a single month would make more sense with Fullerton opening in May with La Habra.