Have any of you SA3R guys ever replaced the small centre coin/medalion circlips? I have two

"coins", and hopefully getting another two from a friend.

However, i will need to get new circlips and i'm not sure how to measure them exactly.

Anybody done this and know what sizes you used?

The coins are 47mm which fit in the centre bore, but there is a small recess that the clip expands into, a little wider than the bore itself.

Don't want to order the wrong sizes.

I'm not good with maths lol.

Any help, if any, is much appreciated
