The local dealer has the belt buckle. You have to cut off the parts that stick out from the back. I used a dremel tool with a cutting saw blade. Then I attached a blind nut with JB Weld and attached it with a stud replacing the original bolt.
The coin I mounted, I silver soldered it to the nut, but the belt buckle is made of material that melts at a very low temperature so I wasn' t able to solder it. Maybe someone with more experience could. The way it's made, even if the buckle part were to fall off, the blind nut will still hold the cover in place. But it seems solid enough that I think it will last forever. Then you just tighten it by hand. I got some very thin washers ( or machinery bushings) and use them for spacers to make it appear vertical when fully tightened.
I'll try to take another picture tomorrow of the back of them and post so you can see how I did it. You might think of a better way, also.