Yes it most likely had an over temp alarm that was part of the original wafer device.That sounds just like the set up in this incubator, right down to the little round light. I haven't found a tag, but that doesn't mean I haven't just overlooked it. The wafer is situated in the center front and the adjusting rod runs out the front of the unit. It was detached when I picked it up, so I don't know for certain that there wasn't something else that should have been with it. I wish I could plug it in and see what works, but the power cord, which was originally one of the cloth covered cords and then spliced at a later date, is so rat-chewed that the whole thing is going to have to be replaced before I can do anything else.
I can show you a pic if you really want to see one.