Strange new problem mostly gone!
My problem with putting my left arm in the sleeve of my jacket has almost completely cleared up! It may have been just a combination of worsening Dystonia and insomnia, plus job stress.
Speaking of insomnia, I've been drinking Chamomile tea at night, right before bedtime. If I drink it quickly while it's still hot, I sleep a lot better but I wake up groggy, and with a mild headache. I tried taking one less Zanaflex at bedtime to see what happened, but I slept a lot worse. Now I'll try taking one less Baclofen at night to see what happens. I may get lucky.
The deviation has gotten a lot worse. My head is turned right, pulled forward, and tilted up, and my left shoulder is hunched up if I completely relax and let everything just happen - or if I'm working. It's making work a little more difficult, but I can still manage. The pain is a little worse, but still tolerable. So far. By my next follow-up (mid-January), my Dr will probably ask for more Botox - and I'll probably be ready for it.