Group-
The E5As were delivered in two “Phases” that roughly correspond with the production of E3 and E6 models. There were variations in the pilot as well. All the E5Bs were Phase I.
The E7s had three different styles of enclosed (“passenger”) pilots and two different types of number boards (older small side style and 45 degree newer type).
The E8 and E9 units were hard to tell apart except for their model type plates and roadnumbers. I am not sure if the different grilles (horizontal fabricated vs. Farr Aire stamped) were model-dependent but the only external spotting feature between the E8 and E9 was the type of gasket on the headlight.
All of the A units had their coupler shrouds/doors removed and the skirts above the fuel tanks completely or partially removed. The E5s also lost their truck shrouds and the applied stainless steel “air intakes” alongside the Mars light were removed and replaced with M/U doors and painted air intakes.
The recent discussion on “Elephant Style” goes into more on the E7/E8/E9 M/U additions.
Charlie Vlk