I'm not exactly comfortable on this side of the fence, but I've mentioned my interest in collecting coins to a few acquaintances. As you might understand, this made me an immediate authority on all things collectible, stamps among them.

As a result, a friend wandered over to my place the other night, and placed this (along with the rest of the series C1-C6 and a few others) under my lens:

All of them are pristine, original gum and untouched since new. Even I had a clue that this group was something cool; what I don't know is just how cool it is. Can someone enlighten me?