I disassembled everything which went well. I then drove around the isle of wight trying to find someone who would attempt to sort it out for me.
Lots of machine shops wouldn't touch it, were a very high price (£25/bolt
) or wanted me to completely disassemble the powerhead (I had the flywheel and head still on there). Spark erosion was either too expensive or it wouldn't fit in the tank.
Eventually I came across Lake Precision Engineering (not in Lake, in Fishbourne!) who have drilled and helicoiled it for only £120. I have not seen it yet but apparently they have done a really good job. I would highly recommend these people as they were the only ones that were keen to do it at a reasonable price and were willing to cope with the powerhead being only semi-disassembled. I will be using them again I think as they also do stainless fabrication.
Hoping to put it all back together today so I can get out on the water this weekend!
(oh, by the way, tried to use a blow torch and mole grips but had no success, the bolts were well stuck in there.)