I wanted to add this coin to my collection:
https://en.numista.com/catalogue/pieces39248.html
So for this coins there are 4 variants. One silver coin Ottawa mint KM72,one nickel Ottawa KM 72a, one nickel Philadelphia P73 and last one silver Philadelphia mint (which on Numista is P73a) . I've noticed that in Krause P-73a is not listed. It is only listed P-73 a nickel coin but with a weight equal to a silver coin. I think that is Krause mistake and P-73 should be the silver coin. Also should we keep the reference P-73a considering it is not listed in Krause?