Away with ye, foul Chits of Doom!

One option is to buy, from a stationary store, small stickers (I have
them as small circles about a 4mm diameter size (that's be about 1/6" to
you Imperialist types). They can be stuck to the bottom of the penny or
washer, and contain a couple of numbers if you write small. So sticking
a yellow sticker on and writing V3 for vet-3 would work. 

My long term plan is to come up with a circular laminated penny-sized
card that can be attached on the figure bottom (laminated so as to be
reussable and changeable with water-soluble staedler markers). It will
have a space for morale, quality and leadership.