Peter - Sadly the archives appear to have been left unattended for many years and don't seem to appear on the current radar of things for the MT to address, but I hope I am wrong. Maybe Mick Forey will be along to update all of us?
After Bill P "retired" his archive services a team was established to record and digitise the contents.
Sadly one of the team of archivists, John Saunders passed away, and the other two volunteer members were neither supported nor encouraged under a previous Technical Director, and they both gave up.
Hopefully this task has been resurrected by the current MT, although the archives are more that of the TR Register than that of Standard Triumph.
Somewhere in Didcot is a comprehensive list of the contents of the archive room so it may still be there....I compiled it and wrote a strategy for managing the contents of the archive room.
There were a whole variety of formats that information was stored in, including acetate film, VHS videos, old photographs.....