Mounting a degree wheel

My guess

Remove the V pulley

Get what here at our "Fasteners" is called a "flat plate washer." These are a big diameter washer that is VERY thick.

Indeed, get a long stud or bolt. You need a spacer or washer that will sit on the outside of the dampener and space the degree wheel out in such a way to make a sandwich, so that the wheel is not warped.

Another source might be to experiment with short "close" pipe nipples or even steel pipe couplers, one that the bolt will go through, and which will seat on the end of the crank. The wheel would then go to the front of that. Use appropriate flat washers on each side to protect the wheel and to add surface area