George, as you are probably aware, I had the same components zinc plated with the silver finish. I'd have to say I think they are a bit too bright for a genuine resto, however, I'm happy because I just wanted them cleaned up.
As I understand it the yellow zinc passivating is trying to recreate the original cadmium finish and the silver passivating is recreating what was called galvanising.
I'm not really across much of this but there are various methods of galvanising.
http://www.azom.com/article.aspx?ArticleID=2629
The specialist plater you use would be the best to ask on what method will best give you the desired OEM finish.
Too bright for OEM finish in my opinion.
Sorry, I cant help specifically with the OEM finishes but I'm confident the hinges, both hatch and doors, were painted over raw cast steel.