I'm bumping this old thread. Our intrepid seller/photrio member
@B.S.Kumar has sold a few of these (Tomiyama Art 170) over the years. To anyone on here that got documents with one, was there any reference data as to appropriate length of lens cones?
I emailed one seller in Japan and that had one with a Nikon SW 90mm f8. They said approximately 48mm which was from face of lens board to face of mount flange ring. At least that's how they told me they measured. I have found with a Fujinon 90mm f8 that the appropriate number is closer to 40mm.
Also of note, the modern Chinese made Technika style lens boards will not work since they are not flat on the back side. There is a raised ring on the rear that will prevent proper seating of the lens board in the camera. So, if you buy one of the "top hat" or extension lens board kits off of ebay, you will need to make some modifications. As usual, I've posted info that would do a lot better with photos to aid in the explanation, but I didn't take any.