The missing link

I completed the conversion of Russian spy-gear a few weeks ago. I can now shoot my eos-bodies on the 300mm f4.5 with a pull on the finger-trigger!
Unfortunately I discovered that the combination of M42 to Canon FD converter coupled with a Canon FD to EF converter elongated the lens too much. This caused serious vignetting, especially when shooting with a FF body. The crop body was not too much of an issue.
This missing link allows me to directly mount the eos-bodies on the M42 lens, hopefully eliminating any vignetting issues on the FF one.
I will go test it this weekend and if the result are any good, I’ll blip it!