Thought I’d updated this after the surgeries but apparently not. Better late than never.
The first was done at the end of March and the second ~2 weeks later on my dominant side after I knew what to expect. Didn’t need general anesthesia. Recovery was quick, so I took lessons a few days after each while covering the site (exposed, surgistrips) to keep it clean. It entailed so little pain that I kept overdoing unawares. No problem with shifting the 5-speed. The only hitch was that the incision on my right side was right over the boniest part of my elbow and bled to one extent or another for at least a couple weeks. The bed sheets looked like the scene of a murder since I saw no point in washing them until they wouldn’t get blood-soaked again each night. It was a king so I just switched sides after the first week.
(Pre-wash meat tenderizer removed every trace of blood from the cotton sheets.)
My left arm is 95% normal (as in pre-problem 1/1/2011 baseline) again and continues to improve as predicted by the neurosurgeon (nerves regenerate about one inch per month). Affected muscles in my arm and hand have regenerated and as far as I can tell strength is now normal, as of course is range of motion. No left shoulder pain since the surgery.
The right had been worse from the outset and is significantly improved though I get twinges and still have noticeable 4-5 finger numbness. When my hands get cold near or below freezing – I ride without gloves when possible – my fingers no longer turn white on either hand but instead remain pink.
I signed up for PT a few months ago because my right arm still had twinges and there was soreness around the shoulder joint, apparently because the interactive complex of muscles and tendons related to my rotator cuff due in part to misdiagnosis as a cervical issue, spent a long time compensating in asymmetrical ways. Right now range of motion, strength and flexibility are pretty good except for a tendon associated with my biceps. That keeps getting yanked on mostly from random lead-rope surprises. PT told me if I quit riding and periodically traumatizing it, I’d be 95% in 6-7 weeks, but if I didn’t it would be more like 6 months. It’s doing better and bounces back more quickly every time I strain it a bit, but there are 4-5 months left to go on that. Some things aren’t negotiable. 
Thanks to everyone who posted for your advice and support early last spring. If this had been rightly diagnosed much sooner, long ago this whole episode would have been history.