I like my simple basic definition of crest and seals -- clay chips with litho inlays and flat rims.

I include these, though with no seal and very fine cross-hatching/linen surface, made by Burt/ASM in the 1990's or so.
The first group are my singles -- not for sale. The second group, you can have for $6.00 each. They are not common, "scarce" I'd call them. When I list them, I give those particulars. Email me if interested.

Robert