I'm preparing to send off most of my engine fasteners for plating. 1970 914-6. I am having a difficult time telling what original finish was as what I removed is a mixture. Really hard to find good photos of unmolested original engines.

Here is my best guess. Does anyone know any different?

• Case through bolts - uncoated steel?
• Acorn nuts - zinc clear chromate (silver appearance)?
• Head nuts and washers - Black oxide (or zinc black chromate)
• Cam housing nuts - zinc clear chromate (silver appearance)?

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