mutant alternators
 

I have three alternators that I acquired over time. One saids SEV Marchal. One saids Paris Rhone. And third one nothing, althought it looks identical to Paris Rhone. What I am confused about is whether all Paris Rhone alternators are internal regulator or not. Is there way to find out if it is internal or external regulator? If so, which external regulator do I use, SEV Marchal or Bosche or ????