I could probably have a bunch of PCBs made up for that price, the board doesn't look very complex. $15 is pretty reasonable, this is really not an urgent matter but it would be nice to make use of that m7957 that I have in my pdp-11/23+ eventually. I am just slowly learning how to use the different operating systems right now. I will keep an eye on ebay if one of these goes up again for a reasonable price.Here's a listing for a M7957 DZV11 distribution panel for $100 (plus shipping). That's a bit much. You could always try a lowball best-offer. You never know, they might bite, but probably not...
https://www.ebay.com/itm/133243188664
Judging by the schematics, the berg connector pinout is the same.
70-19964-00 Bulkhead Breakout Panel
- A B - P1-2
P1-3 - C D - P1-20
P1-22 - E F - P1-25
P1-4 - H J - P1-5
P1-7 - K L - P1-8
- M N - P2-2
P2-3 - P R - P2-20
P2-22 - S T - P2-25
P2-4 - U V - P2-5
P2-7 - W X - P2-8
P3-8 - Y Z - P3-7
P3-5 - AA BB - P3-4
P3-25 - CC DD - P3-22
P3-20 - EE FF - P3-3
P3-2 - HH JJ -
P4-8 - KK LL - P4-7
P4-5 - MM NN - P4-4
P4-25 - PP RR - P4-22
P4-20 - SS TT - P4-3
P4-2 - UU VV -
P1, P2, P3, P4 - Pin 1 - Connected to panel metal frame and connector shells
P1, P2, P3, P4 - Pin 7 - Connected to Berg Pins A, K, M, W, Z, JJ, LL, VV
P1, P2, P3, P4 - Pins 6, 11, 12, 15, 17, 24 - Populated but not connected
So if an H3173-A distribution panel was used with a DZV11, and something connected to the H3173-A distribution panel was driving the DSR inputs, its drivers would have to be able to handle driving its DSR outputs when they were connected to ground. Maybe most RS-232 drivers can probably handle that. And if nothing was connected to the DSR inputs on the H3173-A distribution panel, then it would be a non-issue.