Do you now have a specialist over there that could repair your one?

I have just read this thread again and noted a couple of things, I seemed to missed the fact that it was working on the bench, in actual fact I would not rule out the regulator he fitted seen as I guess the battery light issue happened after you got it back?

Try this, Rev to around 3000RPM and then check to see if it's charging, as regardless of the field excitation if it's working this will start it charging regardless.

Let us know what happened after you tried the above.

Martin