Tom was right, the funny squiggle disappeared when I cured the baffling horizontal problem.
I finally trekked to the regional library and photocopied all of the material in Rider's, which is quite thorough and encouraged me to investigate things more methodically. Checked voltages in the sweep sections, checked all resistors and replaced a few outliers, replaced a few micas just for fun, scoped all the sweep test points and recorded my waveforms in photos.
So many things looked right on the money, yet the picture was so messed up. Why??
I decided to gather all my scattered notes and mark up a clean copy of the Rider's schematic to show all of my replacements and voltage & resistance readings. Then it jumped out -- the stupid wiring mistake! I should have my soldering license revoked
I didn't keep detailed notes, but I think I made the boo-boo early on, before I had realized how far wrong the Sams material is.
Anyhow, the 49-1240 looks and sounds great, and now I can get back on script. The CRT is strong & bright, and the lack of a fine tuner doesn't seem to matter. I honestly hadn't expected much from this E-waste refugee, and I grumbled about the cramped layout along the way, but it performs pretty well.
When I fired up Gone With the Wind to take the customary screen shot of Scarlett O'Hara, my son groaned and demanded that I play something different for a change, so he's responsible for this closeup.
Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html
P.S. I think teevee was also right in surmising that the ticking sound was the horizontal stopping and starting. It disappeared the minute I fixed the boo-boo.