This is my Frankenstein lens -- made from other parts. I bought a cheap 135mm f2.8 T-mount, pre-set lens which the front element groups can be removed by turning it counter-clock wise. The rear element group is also removed. This lens is now basically a tube. I then screwed in the Rodenstock enlarging lens on the front, basically replacing the front elements of the original lens. The lens can now be used, but it can not focus to infinity. The distance between the lens and the sensor is too short. I then added a section of an extension tube. Now it can focus to infinity (actually, it focuses pass infinity but that's ok).
The Rodenstock lens has aperture control, as well as the original lens. I can use either one. The original lens has circular aperture (most preset lenses have circular aperture), whereas the Rodenstock has a six blade aperture. Have not compared what the differences this might make.
First picture that shot against a light source came out absolutely terrible. It flared like there is no tomorrow and the picture is barely usable. Most likely because the enlarging lens was design to pass light from the back to the front, and I am using it the other way around. The flare resistance was probably optimized when light enters from the back.
After adding a hood, and being careful to avoid the flare, I must say I am surprised at how good this Frankenstein lens is. Sure it's slow at f4.5, but in good light, it's excellent. I especially like the bokeh. Not bad for the first attempt :-)