I need a bit more detailed information than that... find me a panel explaining the different color schemes for the different periods, then I'll have something useful to go off... official documentation from BuAer or BuShips only, please.
Regarding the MG fit, I'll need to also see more conclusive evidence of that to make any changes. I don't mind fixing the fit on the Washington, but a photo of Washington does not mean the North Carolina had the same fit. The .50-caliber MGs were very easy for the crew to move around so I think it's a bit of a foregone conclusion to ever expect to get this aspect of the drawing "perfect".