SEEKING CAL 500 SLOTTED MAG CENTER CAP SOLUTION

Hi Folks

So I have these Cal 500 vintage slots with a 4 inch bolt circle. As you can see by the pics, the center caps that I bought encroach the wheel stud holes so using them is a no go. I really don't like the look with the centers open to the hubs and am seeking a solution......Perhaps someone has an idea, or a set of center caps that may work?

The center hole of the slotted mag is 3 1/16 diameter (has not been modified) and the screw holes for the mount are 3 1/2 inches (longest dimension between 2 screw holes).

Thanks FABO

P.S. They are almost 50 years old and will be polished up :)