Were parts such as axle adjusters, brake pedal, etc. plated somehow or were they bare _meta_l...I cannot tell on the parts I have. I have seen some people chrome these parts, but that seems wrong...
Yamaha used various coating on various parts but if you had your bits and piece done in 'decorative zinc' you won't be far wrong in appearance or proofing.
Heres an example from a Monty Cappra 360. about $30aus so cheap enough.
Chroming is good on some parts even if it not OEM. But tape off shafts if you are doing axle or axle ends. Chrome adds thickness and you won't be able to press in past bearing etc if not taped. Chrome requires excellent surface for an excellent finish.