I got 1940 IIIc, red curtain. 365*** + Elmar. The shutter is very smooth, like on Leica I.
The red (more like pink now) is on the side of the curtains facing the lens when the shutter is released, the other side is black.
Its a different material than the later IIIc and also different that II, it kinda remind the I from 1930 that I have.
This, from my gallery here was shot with it: