Continuing on with the Teac. Took a look at how it’s assembled.
Removed the flywheel and clamp plate.
Had a bit of a fight getting in at the right angle with enough torque (ended up with a small wrench on a drill-driver bit) to undo the solenoid finger-bar.
With a bit of a fight, wiggling and swearing the lever arm came free, showing the culprit. 40-year old dry grease.
With a suitable solvent on a Q-Tip, the old grease was removed. A rag on the shaft got the rest.
Choice of lubricant for this task, regular grease.
All mating surfaces given a light coat of grease before reassembly.
There are a pair of microswitches operated by a cam, attached to the tape-run lever on the front. When I undid one screw to move the switches out of the way, this piece of the lower switch fell away. Someone in the past has over-tightened the screw.
Out with the superglue. Glued the corner back on, waiting for it to set right now before continuing.