Well, you guys hit the nail on the head... It was the single lead that plugs into the video out pin on the main board!
I don't recall disconnecting that lead. But, it may have disconnected when I pulled the chassis. It's a tight fit in there!
Now have a pretty fair picture and good sound:
The picture is not as dim as pictured; it washed out a bit when I photographed it. However, there isn't much contrast and the picture does tend to roll occasionally. Plus, the images are "taller" near the top of the picture, but not too bad.
I want to go ahead and proceed with recapping the main board and also the multi-section electrolytic cans. Also just sent the original speaker off for reconing.
Any tips on cleaning the tuner?
Should I replace the 5.6 ohm resistor/fuse? Seems that this is a common problem with the Predicta?
I welcome any other tips from the experts out there as this is the first vintage TV I have undertaken. I'll be glad to update this thread with more pictures as I progress. Thanks!