Todd the boiler jacket continues through the front of the cab all the way to the backhead. Ares is painted green like the cab walls Yes, but i don't think it was prototypical. I think the 315s jacket inside the cab is black. Not sure I bet someone els can confirm that. I would think black would be more common.
And as for the NO windows in the back of the cab. Many years back the old wood cabs started to fall apart. So we decided to build new all steel cabs on both locos. They copied what was left of the wood cabs almost exactly. But we made a few changes in are favor, most noticeable are the cab doors. We made the front doors go all the way to the cab floor.(this makes it easyer/safer to exit the front of the cab) The story for the rear of the cab goes like this. On the wood cabs the rear doors would have opened to the left side of the loco(firemans side) this allowed the door on the engineers side to be out of his way when he needed to exit the cab, and the firemans door stayed out of his way when shoveling.
Now we don't have windows in are rear doors because we don't need them. The windows would have been there so in bad weather when the doors would be shut the crew could see behind them. Are doors are always open, good weather or bad so we don't need windows. also are rear doors only have loops for a lock to keep them shut at night or open in the day so the only way to shut the doors is to put the lock through the loop. wich means you can't open it from the inside. So they stay open. now the back of the cab should have two small window side by side like 315, but because the doors open in there is a small gap between them, and in that gap we put one small window.
In this pic you can see the little window between the doors. You can also see the loops and the lock holding the door open.
Russo loco! A Monday or Tuesday in Oct or Nov we would be running the goose during the week and steam on weekend. And if you want to see the shop ask the crew on the loco or the motorman on the goose, they might just let you see it.