Needed a JW Benson for my collection and just got this but it's a top loader and can't get to the watch shop for a bit to see what the movement is. Wondering if anyone recognized the model and knows what kind of movement it has? It's 34.1mm w/o crown and non hack, no quickset date. It has the Morgenstem punch on one of the lugs so the case is 9ct but I haven't located another one like it in my online search. The case back is marked water and shock resistant, antimagnetic. It has a rotor of some kind as I can feel it when gently shaken. 1960's or 70's is my guess judging from the style and dial but really not sure. It came with a blue JW Benson watch box marked London. I found CYMA, Smith's and ETA movements in other Benson watches and I wonder if there are any other movements they utilized?