what i gather from those clearer video shots is that the cans do not sit in the middle of the heatsinks like the mc2100 does. you can also see the transistors so it looks like a Mc100 to me.
also, the picture Tigerstrat posted is June 1, 1973. same stage, same day as the keith side shot in the GD gear book page 176. also same shots as ed perlsteins who dates them as June 1st. however, there are no recordings for june 1st, so it quite possibly could be May 28, 29 or 30. http://www.musicimages.com/keith_godchaux_01.php
a note of interest from this june 1 photo and the july 12 video is the 4 knob (EQ) box. in the june 1 keith shot it sits facing him on his keyboard, and by july it is sitting on top of jerrys boogies.
as for the effects, i think i am in the TS camp that they are the mu3 and mu octdiv.