I actually got some responses from him just a few days ago to a question I posted on the Bike Mechanics forum concerning my Trek 820 project. And his post included a notice about a community Gilbert and Sullivan operetta production he was appearing in. So he wasn't letting his illness stop him from enjoying life!
And like untold others, his articles on darn near anything bike related have been invaluable to me.
There's a "bikes Sheldon helped you with" thread on the Mechanics forum; at this posting it's over 4 pages.
I found out via a posting on Detroit Craigslist, of all things.