Finally some good news - that starter motor works!!!

After bench tgesting it and seeing it spin normally, I refitted it, then removed, cleaned and refitted the main earth leads, connected my booster battery directly to the engine jump start points and turned the key - and bingo, the engine spun over. Well, it spun over for a few seconds, slowly. The battery booster had died.

It's now on charge overnight, I'll try again tomorrow.

With the engine turning over, I'll be able to test if the spark plugs and fuel injectors are firing, if they are, I only need to get the fuel pump running and I may be able to give the engine a test run.

I'll keep posting!