Theory #1 - It really is a Cut'n'Shut P7 and the left over bottle mount is a reminder
Theory #2 - It is a clever way to stop you from lowering your seat post onto the top of the URT, however if you did drop it down fully it would make an impromtu rear lock-out
Theory #1 This has always made for a great topic of conversation, however since yours is 12 months older than my Canti one,
I doubt very much that by this time they were still using tubes off a P7 if indeed they ever actually did,
so you can only assume this theory is no more than a funny urban myth.
Theory #2 Chuffing boring this one, but most likley true, especially as Full Boucers were reasonably new and most owner
would be migrating across from a hard tail, + you could right royally f**k your bike up you in an absent minded moment.
However I've never seen anyone have a bolt in this boss .... so I'm not convinced that Theory #2 is correct.
I think we need to tap up the Oracle of Delphi, the all knowing Mr Sinnerman... I bet a £1 he'd know or at least know
someone reliable who does !