I made a crude sketch for how Lydia and I envision the connector situation on the back of the vme crates to be solved. Essentially the side panels of each crate extend about 2" (52 mm) beyond the edge of the DIN connectors. This is plenty of space for a simple PCB board. The connector of choice is D-Sub. We can split the 64 used pins into 2x 37 D-Sub OR (2x25 pin + 1x15pin). The former has fewer cables, but a few excess unused leads. A quick google search showed me that it is much cheaper to get twisted pair cables for 15 and 25 pin D-Subs. From what I remember, the used pins on the DIN connectors are concentrated on the low numbers end and the high numbers end, so might not need the 'middle' connector in many cases if we decide to break it up into three. I have to check this with Lydia though.

The D-Sub connectors would be panel mounted, for which we need a narrow panel piece with dsub cutouts. We can run horizontal struts across the vme crate from side panel to side panel. This way the force upon cable (dis)connection is mostly on the panel which is attached to the struts which are attached to the crate. This will also prevent gravitational sag or cable strain from pulling on the DIN connection, and we can use twisted pair cables with backshell, screws, and strain reliefs.

I was lookng into getting started with the PCB when Altium complained that the license is expired and to renew it. This is a relatively simple board layout so some free software out there is probably enough.