Sof1a the S1nger
I only have one from 1918
I don't know how to work out sound or anything
Maybe since the thickness is different I could tell by that? But I don't know how to measure thickness
· You would not need measuring equipment in this situation for the thickness -
just hold the two coins against each other side-by-side and see if they are the same.
· For the sound I would drop it onto a table from a few inches above and hear the sound it makes.
Then repeat for the other coin - so 1918 should make a different sound from the presumably
second version [by the colour] 1920 coin. With it being 0.500 then other metals in the mix make it different.