In 1972, the Wittnauer Mint tried a collaboration with American Bank Note Company. Wittnauer produced 36 sterling silver medals commemorating all the U.S. presidents to date. ABNC printed engraved presidential portraits as counterparts. A hole was die-cut in the paper below the portrait for the medal and the set was combined in a Lucite holder. The high-relief medals -- both a little more than a troy ounce – had a pewter-like matte finish. Wittnauer also issued a gold-plated proof-like version, but only the matte-finish medals were used for the ABNC pairing. These show up periodically on eBay as bullion, but often the medals were broken out of the case, which was tossed. I've been able to find 32 intact, out of the 36, but I'm missing presidents Tyler, Polk, Lincoln, and Andrew Johnson. I'm actually more interested in the engravings. Has anyone come across these? If you have a complete set (or just the four I mentioned), I'd like to see photos or scans, in order to document which engravings were used. Thanks for any help you can provide!