...
but I wonder if the 1963-1966 Opel Rekord indicators is really original?
Why not? When they built the prototype, they took the parts, they could get. These indicators were by Bosch or Hella still in the range, that's it.
Btw.: I know some Saab-freaks (the family, who imported the first Saabs to Germany before Saab has founded a sales office here), who told me that the 1970ies Saabs are widely assembled with German parts. So the most interior and electric parts are made in Germany.