Wow, that is a real conundrum. If the split stem and the movement date (1964) are correct it predates the Manhattan but comes from a watch with a similarly encased movement. The dial has the markers in a round placement, however it could still have been a square or rectangular case, held together with 4 screws or a snap on case back. I note there is no Rado brand on the rotor, however that may not be unusual for this movement or the rotor may have been replaced at some point. Very interesting piece, I'm sure it'll cause lots of discussion. Hope you find an answer.
Originally Posted by jethrobodine