I wouldn't worry too much about NMF v silver painted finish Vraciu. I'm just going to switch off the layers on my B-29 template that show the tone variation between different individual panels as well as the layer for the darker silver painted areas that I use for NMF aircraft B-29 skins.
The issue is more a question of how polished the finish is. The CAF's silver-painted B-29 looks to have a relatively dull finish compared to many WW2 B-29 photos I have seen, but their P-51 looks a bit more shiny and polished than the WW2 finish. So the specular, environmental and power maps will need to be adjusted one way or the other to match the required finish.
My MA version of the C-47 will lack the CAF logos and will have a duller finish to the paint. I'll also add back all the paint chips and dirt that I'm turning off for the CAF version.