I lasted my week in restoring this very old converter 
Just for training me, because it is a rack... I published, on line, many photos describing
several phasis of the restoration. Many do not have any merit to be published
(no interest, they are very similar). It will be able, in the futur, to compare status.
We can see that cleaning and preserving processes lead to loss 5 transistors.
This rack seems to be incomplete, because i think it must have 58 cards!
I have another converter, quite similar, but with lacking cards. It will be restored ...another
month... Have a look in OA-1001 restoration project.
You can read probable specifications of this converter by clicking this link:
Serel 12080 ADC
Remember that the manufacturer picked a lot of cards to fix another computers.