Ive never heard the term "Merchantile Novelty Co. Inc.", but it may be the company that made the B18's. There is a picture in Lipsets Encyclopedia of the adhesive strip that attached the B18s, but its may not show all the fine print on it. the only writing I can make out is "An Attractive Novelty Attached to this Package" and also a tobacco factory district number, similar to whats on back of a T206 card.
info on B18s
The felts are usually called "B18 Blankets". They were folded (sometimes inside a small envelope) and attached to the outside of packages with an adhesive strip to packages of Egyptienne Straights Cigarettes. They are from 1914 and measure roughly 5.25" on each side. These blankets are often found sewn together on quilts or pillow cases. There are a couple color variations for each player, with 90 different players in the set.
