Delilah, the Brother monogrammer pictured worked on a low shank Kenmore (which is what I tested it on). It was stiff and needs lubrication before I can tell how well it works but it did form the letters which were maybe 1/2" high. I put it away for now as I'm getting ready for a trip and don't have time to futz with it right now. Good luck on your search.
Thanks all for the suggestions. Goo gone usually works well and I have some.