Push on 30mm to 39mm step up filter ring for Meopta Flexaret II III IV V Va (and maybe other cameras)

I own a Meopta Flexaret Va camera. This camera takes push on filters. I just have a yellow one and a close up adapters.

On my rangefinder camera, I use a Leica Thread Mount Voigtländer Color Skopar 35mm 2.5 lens that takes 39mm filters. 

I have a small collection of nice filters for this lens, and I would like to use them on my TLR camera. After just holding one in front of the lens I saw that these filter probably did not cover the controls, and probably would not introduce vignetting (though I have not tested that yet).

I designed this to fit snugly on the taking lens of the TLR, and allow screwing a filter on the other side.

The filter threads modeled in are sligthly oversized ISO threads with a major diameter of 39.25 and a ptich of 0.5mm, with a nice lead-in flange added. Screwing filters is easy and they fit well printed on my Voron 2.4 out of ABS plastic at 0.1mm layer height. 

No warranty of any kind, I cannot guaranty that an expensive filters does ends up on the ground or is damaged in any other way while using this adapter

Printing

Print it with the threads facing up (like it is in the 3MF file). Use snug supports. 

You need a well dialed-in printer. I recommend using a standard 0.4 nozzle and printing at least the threaded part at 0.1mm layer height (can use variable layer height and print the rest of the lens at a fatter setting)

I recommend ABS plastic. The slight flexibility help the adapter to hold on the lens

I suppose a similar design could even be machined, but I know nothing about that. Black plastic works fine for me.