I came across a hardcopy manual for MDB’s MLSI-CR11, which is a QBUS Card Reader Controller.

It appears to be similar in function to the DEC CR11 UNIBUS controllers (M8290/M8291) except that it has a 50-pin I/O header instead of 40 pins.

Freshly scanned manual can be found here -> http://avitech.com.au/?page_id=951