Here are a couple of photos that may be helpful to you.
This is a photo of an M4A3E2 with Patton's 3rd Armored Division taken sometime around December 19, 1944.
Here are 2 tanks from the 4th Armored Division, 3rd Army taken in Alzey Germany on March 20, 1945. The vehicle on the left is an M4A3E2, recently rearmed with the 76mm gun (authorized by a U.S. Army field order in March 1945). The vehicle on the right is an M4A3E8 with HVSS using T66 tracks.
This M4A3E2 was photographed at an ordnance depot Cherbourg France.
Here is an M4A3E2 photographed near Langerwehe Germany. It is using the older 75mm gun. Notice the extened end connectors on the tracks. All M4A3E2's had these fitted to help deal with the additional 10 tons of weight (as compared to a standard M4A3 with the 76mm).