What a mess! I need to make another muslin because I made so many mistakes that I'm not sure I've even got a draft I can trust enough to fit,
The collar wasn't correctly sized to the shirt body, but with some tucks I got it to work a little. My right should droops so badly that I had a wad of fabric on the front, so I sewed in a curve. This improved the fit, so I'll modify the paper pattern. The whole shirt is a little snug. I'm either overweight, or it really is snug .. probably both.
Overall, I do like it. This is the first collar, albeit badly made, that feels comfortable to me. Just a little less tight, and maybe more room in the armscye.
We'll see. I'll try a second with cheapie fabric again. Gnight!