Most of the car/boat trailer builders around here used to use Ford pickup take-off wheels on their trailers. With appropriate trailer tires on the wheels.
It would be nice to have the wheels match the car on the trailer, but it's really not needed. Considering that the trailer is "a tool" to use, which can see some wear and tear.
IF you want to do something to make it more distinctive and not spend a lot of money, some spray cans of GM "Medium Graystone Metallic", 1978 pikcup truck color, or something of that nature, can do just that. Wash them in brake clean, tack off, then shoot the spray paint. A bit darker in color than the "dull" silver on the '71 Z/28 wheels, for reference. A nice darker metallic color that looks good. Ought to be a similar Chrysler darker gray color, I suspect, to "keep it in the family". Might even add a red double pin stripe around the edge of the rims, too?
Just some thoughts,
CBODY67