I started sorting through my father-in-law's stamp collection today. I found this interesting. What do you think the coins grade out at?
That is part of a two stamp set "Banking and Commerce", The other half shows I believe the reverse of a Liberty head double eagle and a seated Liberty coin, I forget the denomination. There is another coin stamp as well. In the 70's they experimented with a smaller size stamp and it pictured an 1877 indian head cent.