I was drawn back into tilt by the Mirex thread in this forum. Got me a Mamiya 645 45/2.8 and built me one.
The "bellows" is a leather lens pouch. I attached this with the three screws holding the lens mount. One at a time. The eos mount is just at spare adapter glued to the pouch with super glue (glue before mounting the bellows to the lens...).
It is not a very predictable solution but for roughly 100 euros it is a creative tool.
I have experimented with a macro rail and a mini ball head to be able to lock the lens in position but it needs more tweaking before it will do the job. Until then I will have to shoot handheld.
Well done...I've been thinking of doing something similar with my M645 lenses for years.
I had the 45mm f2.8 N but it was soft compared to my 35mm format 50's so I sold it.
The one I'd like to get for tilt/shift experiments is the 35mm f3.5.
I like it too! It's not as secure as a Mirex, but it gives you a lot more movement, with more artistic possibilities. I really like it. Simple and effective. Well done.