I am also a history teacher and WWII buff and have written up a puzzle cache using the enigma simulator, but I haven't placed it yet. Still looking for the right place. I was not going to encode the clue with enigma, but just the coordinates.
The cache page would give a history of enigma, then the rotor, stecker settings, etc., and then have the encoded coords.
Still thinking about it, just haven't gotten it done.