It comes from 2005 Topps Rookie Cup Baseball. It's part of an insert set called Original Relics. They're strange beasts that I hadn't heard of until I stumbled across this beast. Basically, Topps appears to have started with a 1971 Topps buyback, which was promptly sliced in half. The window was cut out and the two halves were pasted onto a think card stock with the gold foil Rookie Cup showing. Talk about a Franken-card.
Cards in the set were limited anywhere from one to ten copies. This Morton, which will be going into my Expos collection, is a 1/1. It's even got the 1/1 hologram on the back that was fashionable back in the day (I'm not sure if they still are).
I'm not too happy that his first name was cut off the facsimile autograph, but this certainly is a unique concept and is a much more meaningful 1/1 compared to most. That being said, this is a gimmick card and one that I hope Topps just lets lie.