Which of course it didn't start then.
Its always just been a gimmick. Yes protoQuo may have started but it wasn't Status Quo. Not until 67.
Not that Quo knew about it themselves. The band had already been created in 1967, FR,AL,JC were its members since 1962. RP wasn't a creator of a new band, he just got an invitation to an already existing band (which was signed to a RC since 1966 and had released 4 singles), because its producer thought there was a need in another vocalist. Rick's arrival had nothing to do with the band getting the new name (The) Status Quo. It's not even clear whether Rick took part in the recording of POMM which was released as a single in the late 1967.
Here's a few anniversary dates:
1967 - Spectres/Traffic/Traffic Jam the band celebrates their 5 years anniversary (Jess Jaworski, the original keyboard player gets an invite and he tells about it in a 2000's interview to Dutch Quo fan club)
1975 - Quo release ROLD-live EP to coincide with the band's 13th birthday
1982 - Quo celebrate their 20th anniversary, 1982=XX
1982 - John Shearlaw publishes "THE AUTHORISED BIOGRAPHY - THE 20TH ANNIVERSARY EDITION" (a renowned version of "THE AUTHORISED BIOGRAPHY" from 1979)
1986/1987 - John Shearlaw publishes "THE AUTHORISED BIOGRAPHY - THE 25TH ANNIVERSARY EDITION"
1990 - Quo's then new manager David Walker wants to make some event that same year, he takes a Quo biography book and finds that Francis and Rick met in 1965. So a new "anniversary" is made up. That's when and how the regular chronology got tangled.