Haven't seen a lot of talk about these lately. They are a fairly inexpensive (*relatively speaking) way to collect. This was $106 after tax and shipping from a recent Brockelman auction. I kind of like the staining on back.
Copied from the Oldcardboard site-
Set Summary
Produced by the American Caramel Company of Philadelphia
The E91 set is unnumbered and contains a total of 99 cards
It is divided into three subsets (E91-A; E91-B and E91-C)
Card fronts use generic color artwork with white borders
Backs contain a complete checklist for each subset
