Just to put a coda on the magnet issue, I corrected the pitch as phishrace advised (turned out the digital angle tool I originally used was not accurate). The situation improved dramatically, but not completely. I reseated the connector to the magnet and tweaked the height just a bit and it has been tossing the ball up and over without fail during the course of several games. I thank you all for the help as I muck my way through adjustments and fine tuning and problem solving. While I was in there, I rebuilt the upper flipper and was rewarded with significantly snappier flipper action. It's amazing how much better and easier the game is now (not that it is an easy game), and I was enjoying it immensely before the improvements. I still need to fine tune the exit flap for the shooter lane, and the Stern or Cliffy(?) protector around the scoop needs to be replaced. Almost there.
Thanks again for the suggestions and advice.