Copy/pasta from my Pinside post!
Another update!
I replaced the right and left flipper assemblies as well as the kickback coil tonight. My soldering still isn't great, but this was an easier (and significantly less stressful) job than the board work. As far as I know, the only major "repair" left would be the female side of the GI connector. The only thing left for me to do is finish cleaning all the ramps/plastics/etc, install LEDs while cleaning out the inserts a bit, and reassembly.
Once I get everything reassembled, I'll be able to do a full switch test to determine what may be causing the trough opto problem and the ball lock issues.
Few pics of my 3-hours of work tonight! Kind of boring, but this is part of it! For the record, the left flipper wasn't needing to be replaced necessarily, but I figured that I might as well just get fresh left/right flipper assemblies entirely. The coils on both are still good, too. Having an extra isn't the worst thing in the world. If nothing else, I can pawn off the used left flipper assembly for $15 and help someone out, haha. The right one seemed OK, but the playfield mounting bracket was missing a screw/messed up, so I figured I'd just replace that whole one, too. Maybe could have saved myself the cost of both assemblies, but it's relatively minor overall considering the age of the game (and I'm only assuming they hadn't been replaced).
E: The pics are just the old bad right and bad kickback, as well as the NEW right and new kickback. As I said on Pinside, my soldering is slightly improving. But what matters is that the solder will hold and allows the game to play/function. That was my goal!