>ouch<
Well the rust dissolver worked a treat, a breaker bar wouldn't shift the 15mm nut yesterday, and today an ordinary ratchet spanner took it off.
A long winded job, at least the belt went on easily – tales of special tools on the net, but a 1/2" drive breaker bar fitted the square perfectly and plenty of slack to slip the belt back on single handed. More of a pain fitting the engine mount back on, one bolt was very tight but the old trick of swapping them over helped.
Best of all, it's charging now. Will dissect the old alternator to see if it's repairable. If I can fit a £7 brush box and get it working, I will.
Neil