TT wrote:
Does anyone actually know the thread dimensions and type of
thread on a Rega TA base - the bit that bolts through the
plinth.

Having a quick google, I come across the description 32mm A/F [1] and
someone's upgrade story finding that a bicycle spanner fits to tighten
it. Knowing the story of Rega's beginnings could it be possible that you
might find matching components in a cycle shop? [2] :-p BTW I also found
claims that tightening the base nut too much could be detrimental to the
sound...

Probably worth giving Origin (the arm rebuilders) a call - they may tell
you if Rega don't. I've got a P3-24 which one day I'd like to mess about
for changing carts from Rega's (fine) own. I'm just a bit tight paying
for a set of spacers at the moment, £15 each - for things stamped out of
sheet metal ;-)

[1] - as useful to finding thread spec as ...
[2] - crazy project idea, build a Hi-Fi turntable out of bicycle bits?

--
Adrian C