Last night's success led to a change in the collar this morning. I decided to make both the upper and lower collars from this gray-brown textured silk. I'm really please with the way the coat is shaping up now. I had already cut a collar from silver silk dupioni to use as the under collar, so I just used it as the interfacing. This textured silk piece is actually a bit sheer so that gave it more substance.
I tried an old Nancy Zieman trick for making the collar. First I decided that I wanted the stripes to run vertically at the front edge, just like the pocket bands do. This was going to require cutting the collar off grain, at a minimum. So instead of an upper and lower collar, I placed the opposite end of the collar on the fold, lining up the stripes and cut (in effect) a left and right collar. This requires a center back seam and the front edge ends up on the fold. It looks lovely right now. I hope that when I attach the lining and facing, I'm still happy with this technique. I think it's all in the grading and I won't know if that is OK until I attach the lining and facing.
I'm thinking that I may use some more of the brown-gray textured silk as some kind of cuff on the sleeves. I'll set the sleeves in first to see where they hit me on my wrist. Now I need to go read that article in the latest Threads - something about slow sewing. It can be very satisfying.