Well, I was skipping around for a while, anyhow. I tried the welding process, saw several flashes, and after about 15 tries (checking the emission after each attempt), the weld finally worked. The emission bounced back up and the CRT looked good on the life test.
I left the CRT on the tester for about half an hour, curious whether the fix would hold up. When it seemed OK, I reinstalled the chassis and powered it up.
Yay! Wahoo! Looked great for about five minutes . . . until it faded again
I guess the weld wasn't strong enough to last. Perhaps I'll try again tomorrow.
Phil Nelson