My guess is the 2nd to the left is the earliest scheme (1928-- out of receivership), the one on the left is next. I think this scheme was used in 1934, at least with car 714305-- the round roof rebuild). I think the car third to the left is in the 1937+ scheme... though I'm not sure as I thought this was the scheme for 40' and 50' XA double door cars. But it would be a repaint so maybe they were more flexible on repaints, especially old double sheathed cars.
I have no idea what to think about the roofs. They could have been built by different builders... the 1928 single sheathed cars had quite a few builders.. and maybe they are original. But the one on the left, in my eyes, matches the roofs of cars farther to the right... but the 2 cars to the immediate right look like old pre-batton roofs? I don't usually care much about all the minitua but the roofs are quite noticiable.
Now I see vertical break wheels on both types of roofs. But the 'roofwalks' on the ends of the running boards look different for each style?
I only know this from having an NTRAK module at the Tacoma mall years ago... 1980s I think. It was great having Milwaukee equipment as there were a lot of ex-employees walking around. I had a bunch of ~1928 type cars that had Murphy panel roofs... which I knew was wrong for the Milwaukee but I liked them and they were close enough for me at the time. One of the passerbys was asking about the models and I told him I figured the roofs were wrong. He put out his hands that had some scars on them. He said he used to work for the MIlwaukee and had cut up his hands replacing wood roofs on Milwaukee cars with metal roofs. So I became more interested in having a variety of plausible roofs.
Looking at more running boards, to me it looks like most are wood. Even the steel ribbed car on the left hand side-- to my eyes-- has a wood running board. So the switch from metal to wood running boards on Milwaukee ribbed cars must have come quick if this shot was from June 1941.
Anyway.. inspiring image. Thanks! --Kirk Reddie