The blue box does indeed have 6 dimmers, with two female 20A 2P&G receptacles per dimmer. This unit is a "Luxtrol" made by Superior Electric. A similar unit was manufactured by Altman, using Luxtrol dimmers. However, that unit had the outlet panel on the back, had a seventh handle as a master, and used shorter plastic "knob" handles rather than the multi-colored tubular plastic handlles supplied by Superior. The capacity of the dimmers cannot be determined since we can't read the breaker ratings. They could be either 2500W or 3600w each. Wait, you say--how could a 3600W (30A) dimmer be connected to a 20A outlet without a supplementary overcurrent protective device? Hah, what's 10A between friends? In those days (1960-1972, approx) we clearly didn't worry much about such trivialities.We gave students enough time, correct? If not, please delete this.
There are 6 dimmers in the blue box [I believe] but do not know the manufacturer.
The two black packs are LMI or ETC [depending on year made] L86 portable packs. If you have ever carried one, you question the term, "portable." Based on the fact that there are 20A stage pin plugs laying on top of them, I would guess they are either 12x20A dimmers or 24x10A dimmers. Hard to tell from the pics, but I think there are breakers on the modules both on the left side and the center which lends it to 10A dimmers.
As such, I venture that there are a total of 54 dimmers.