Well, I can get you a complete new engine easily enough

I know a few places locally that may have the appropriate spares for either the Ford Ranger (european designation) or Mazda Bongo R2200 (japanese designation) engine. i can make a few enquiries if would help. It would probably have to wait until monday. That said, on Sunday I'm going to the Beauleiu International Autojumble, and it's possible there might be such a thing there. I'll keep my eyes open.

pca

OK, I've put in a search request for the appropriate part on an online breakers yard search engine that I've had good results with in the past. We'll see what happens.