I still have a like new Bowers polarizer in 30.5mm that I had for my 35S (that I sold a couple of years ago). I rummaged through the drawers at my local old fashion camera store that's been in the same location since 1952 (helped that I used to work there) and found Rollei filters for it. But I sold the filters with the camera. It's amazing what is still stuck away in drawers of old stores, if the store still exists. Good luck with your search.