Thanks everyone for the comments and advice.....today I "finished" Hot Hand, I found an old solenoid in the junkbox which I think came originally from a photocopier!, turned up a new shaft and it works, unsure if the coil resistance is correct but its working at this stage. The steel bumper acutator...that was a bit more difficult, I got the old one out, banged it flat with a hammer and cut a new one out (which is 'sort of" the same shape as the original) of some scrap with a hacksaw and bent it back again...amazingly it works! ,I bet the restoration blokes are vomiting reading this...but at this early stage of my new hobby Im just happy to have a working machine to play on....anyway, got it all back together and after a couple of games the machine locked up and the displays froze, luckily all my electronics knowledge was from the era of this machine and after checking all power supply rails (ok), the next thing to check was the CPU xtal oscillator which was dead, a dry solder joint on one of the crystal legs.

All the best