[Jack21]

I wouldn't use aluminum for a spinner that held the wheel in place, period. British cars with spinner mounted wire wheels way back when were chrome plated brass If I recall.

Aluminum is fine for decorative spinners, where the wheel is held on by lug nuts.

To prevent the galling you describe, either use the stainless washer between the two surfaces, or make (or find a source for) stainless spinners.