Mopar 15 inch wheel question?

They are a common wheel, so getting some should be easy and relatively cheap.
The first place that I would look in the junk yard would be a late '70s or early '80s pickup/van/or big car like a Cordoba.
Junk yards commonly have piles of wheels and tires laying around, so you could sift through them and find something there.

Generally, A-Bodies didn't come with 15'' wheels from the factory so unless someone changed them in the past, I doubt that you will find one that has some on it.......