HI,
SHould this be brass or cast iron, painted?
I have inspected 3 cars, two are black painted, and one is brass.

Neither.
Most are cast in bronze. But I have seen some forges steel ones, not sure there original.

All Stanley iron parts are forged steel.
I can’t think of any that were cast iron. Except some of the pluming fitting like the blow down elbows.

Rolly

When the Stanley cars were delivered to the dealer, everything was usually finished. Either it was plated nickel or it was painted. Unfinished brass was accepted as unfinished. Usually anything that was left in brass or left unfinished was added on after the sale of the Stanley. Examples of brass add ons: windshield, headlights, rear view mirrors, speedometer, etc. The 1900 Locomobile is a good example of plating. If it wasn't plated nickel, then it was painted.

...I should have said steel, painted
I will make this one bronze, then