Having sold my spare Seiko 6159-7010, I have managed to find a nos Trematic Moonphase from 1965 using Felsa 693 movement Felsa Bidinator (Also used by Breitling). It's a large stainless steel case measuring 37mm excluding crown. The calibreFelsa 692also called Bidynator, is the first self-winding movement with bidirectionally operating rotor. A mechanical switcher on gear basis, introduced in 1942, determines the direction of motion of the weight segment. the Felsa 693, is automatic Moonphase.
I have traded my modern Hamilton for this vintage Fortis Moonphase using Valjoux 90