Good question. I bet you a pound to a bucket that this is a hand lettered set. Also there is no room to swing a squegee on these frames - barely room for a clean pull, if you know what I mean. Nice Q. Can't think of a practical application - I expect something will turn up.

One possibility, suggested by the extra S, T and E: someone was making movable letters for a sign board. I have a few sets of these, along with a nifty backlit sign. The letters are a gothic style (something like yours), and they're printed on heavy, white plastic cards. You make up the words letter by letter, sliding the cards into a slot on the front of the sign. I got the whole deal for a few bucks at a yard sale. It even included a box of dingbats, arrows and punctuation. Couldn't afford NOT to get it! (Now guests in my living room amuse themselves by making absurd messages.) Just one possibility.

Skylar

Thanks for the feedback. Skyfein, I thought about the moveable letters before also, and that makes the most sense to me. Now that I think about it more, the inclusion of the ! and the % but not any other glyphs seems important. Stores advertising sales and other events would definitely use 50% off, and SALE! Although there aren't any numbers. Makes the most sense though. Thanks.