My previous bongo was also T reg 1999 and def had a silver tent.

I had no idea the colour indicated the year of the tent.
I don't think proving it one way or the other will get me very far, but when you say 'easiest' option, I presume you mean less nearimpossibleforme option? I, of course, wouldn't know where to start but would it be a simple thing for a standard mechanic to do? Bongo specialists I would imagine would charge a fortune?
Thx again for your advice.