Well after marathon testing and interweb trawling, I went to my local parts mega store. Cough, how mooch? A range of prices but none around £69.95 I can tell you. So, sent it to a local place for a rebuild. Half hour later - yep, it's shagged but not repairable. There are no parts available other then to replace the entire winding. They do nothing but alternators and they said 'no'.
Rang Mr T in the end and my usual contact worked me out a deal as a 'taxi driver' and did it exchange for £233.03 all in plus £20 in M&S vouchers! Coming Friday.
Damn.
Chris