I have one of these lenses for Hasselblad that won't infinity focus and I read that it's because it is missing its little drop in filters. These seem to be hard to find. I'd love to buy something like a damaged one I could remove the glass from or even figure out a way to make a spacer. If I knew the exact dimensions of those filters maybe I could have one fabricated. But I'd rather find one. I have emailed Zeiss but have not heard back. Any suggestions for me to find a Bay 26 filter or spacer? Thanks.