I was in my local camera shop yesterday, Kitamura Camera where they have a cheap bin with lens caps, straps, used filters, etc and sometimes I come across some decent stuff. So yesterday, I was looking for some 49mm protector filters for my Takumar lenses and happened to find a Kenko MC Portmate A filter, with box and case for ¥500 ($4.50 USD). I'm not sure if it's used but the filter's box is definitely old but the filter is immaculate.

I couldn't find any English information on the web whatsoever, but quite a few in Japanese, so maybe the filter wasn't sold outside Japan. But basically it's a softening filter for portraits. Luckily, the instruction manual had both English and Japanese instructions so I scanned the English one for your viewing pleasure. It states that the Portmate A filter is for 85mm to 135mm lenses, so my Super Takumar 55mm (82.5mm with 1.5x crop factor) should be fine.