When first researching the 528th, I came across references that I didn't completely understand, but seems to be common military abbreviations for the type of unit. They also sometimes differed, like:
If I spell out the second item, it would read, 528th Field Artillery Battalion (motorized, 155mm cannon/gun, tractor driven)
The first one indicates, in error, that the Battalion towed howitzer guns. So what would be difference, you ask!?
The 155mm Long Tom Gun:
There are three main types of artillery, distinguished by muzzle velocity and firing trajectory:
Org Chart: When researching Corps level Artillery Battalions during WWII, it was difficult to find the structure or organization of the 155mm Long Tom Tractor-drawn Battalions. The chart below was pieced together from several sources and hope it to be accurate in showing the formation and equipment. Essentially there was a dedicated Battalion HQ, Medic, Service/supply and 3 Battery groups within the Battalion. The 3 Batteries (A,B & C), each had 4 units of M4 High Speed Tractors hauling 155mm Long Tom Guns. Each battery additionally had a maintenance and supply group managed by the Battery HQ.
Uniforms of 1944/45 Artillery: Here are some photos found online that help paint the picture of the Artillery uniforms in WWII. While there are photos in other pages, they can be hard to see due to their low quality.
Interesting links when researching Artillery in WWII:
Some promotional material during WWII showing the Long Tom 155mm Gun
Check out this 155mm Long Tom poster for the home front, asking civilians to save their tires!
Recruitment poster for the Coast Artillery Corps during WWII