I have now got the generator engine to run. Its a 2 cylinder Mitsubishi diesel of about 10hp. The problem I had was the control panel had been unwired to aid removal but no note of where they went was kept. This was not a problem as I was sure the Vetus data sheet would cover this. Indeed it did, however it was in every European language except English!
The back of the control panel
12 wires needing a home
The problem was eventually solved by Ian Bagnall at Vetus UK head office. He very kindly tracked down the right information and emailed it to me in under a day. Many thanks Ian.
Having rewired the panel, fixing up a temporary fuel supply and return, connecting a battery, and shoving a hose up the water intake tube, a few bouts of cranking and the engine fired into life.
Now all I am waiting for is a chap to come and look at the alternator end. Hopefully this will be next week. I already have a price for a complete new unit so I know the worst case cost.