Want to Buy wtb: 27mm push filters/Lubitel filters

I'm looking for 27mm push-on/slip-on filters -- specifically some ND filters (2 stops is ideal). Honestly, I don't even know if such a thing exists, but some Googling/eBay browsing suggests that there are a variety of filters in this size. I'll consider anything with an equivalent filter factor. I need filters that will fit a Lubitel2. Thanks.