A LATE CLOSED BACK AC100 CAB
A real heavyweight due to its closed back. Made by Gla-Rev (the stamp "G-R" on the inner shelf). Used for many years with an AC50. At least two other English trolleys are known (both containing Goodmans speakers) with incised rather than blind-stamped lettering on their handwheels. See this page. Two of the original casters - English open type rather than American hooded - remained. All have now been replaced.
Drivers are a type of Celestion G12, sprayed "poly grey", probably T1225s. The wiring is extremely tight and will need to be unsoldered to allow removal of the speaker (for checking of the code stamped on the gasket). One has been replaced by a T652 silver alnico, probably from an early Selmer amp.
As the back panel is 3/4" thick, it extends further into the cabinet than a thinner open back panel would, and so has two drilled recesses to accomodate the Midax horns. The two drilled recesses were made before the back panel was blacked and tolexed. The hole for the XLR socket was made after the tolex had been applied.
Note that the black internal wiring with coloured sleeves at the solder points is found in certain 7-series amps produced in 1966, as for example, the beautiful 710 below. The coloured sleeves are just visible in the third pic.