Posted By:
hankronIn them thar old days (before N172s) they use to slip some small tintypes into little custom 'cards' just like like this. The tintype would be put into a slit and the hole in the middle allowed the image to be viewed. Often called tintype CDVs, as they resemble regular CDVs. Bright way for a collector to store a trimmed N172, but the two were not designed for each other.