ACT and CMI Unibus boards

[shadoooo]

Hello,
just received some Unibus boards, some are from ACT, one from CMI.
I would identify these boards.

The first is a big hex board, marked ACT 10046: on front side has two 
50pin connectors,
plus two female edge connectors on the left side (some sort of narrow 
bus extender?).
There are some resistive terminators onboard near one of the 50pin 
connectors.
Very strange board...

The second is a quad board marked ACT 10039: it has four 40pin connectors,
two on front and two on a side.

The last is for sure a RAM board, as it includes an array of 16x9 HM4716 
ICs, with a total of 128KW.
It's from CMI ON 207-010-300 and it has a lot of wire-wrap  jumpers for 
configuration.

Anybody has some knowledge over these boards?

Thanks
Andrea