My model is intended to represent a museum quality prototype
I am a bit reluctant to paint polished aluminum and stainless parts, so, for now, I sprayed the wheels with Tamiya clear.
Tankerman’s painted Maserati wheels are a more accurate representation of the prototypes
I think it will take considerable time before unpainted polished aluminum and stainless MFH parts will tarnish.
You can polish the MFH white metal parts (for example, see the air intake to the carburetor on my 159M), but they will tarnish fairly quickly if not protected with a clear coat