Al, actually there are now 5 variations not 4 I know of.

There is 5 variations of this design known:
#1 - .13 oz. Tiny one Marked Sterling on Hotel side
#2 - 1 oz. size / not numbered on rim
#3 - 2 oz. size / numbered / 1974 not 1994
#4 - clad
#5 - brass

Dennis