After a long time an update on PPU's #200 of 1939
I ran out of the small decorative screws and have to wait for my order.
Still not sure about the shell's color - later diesels were plain black. So far I've no info on #200's color. From the b&w phottos it seems that the shell has a lighter color than the frame - however this could be also an effect of light incidence or color's fading.