Nice work, and thanks for the posts! Ribbon speaker work is, as you found, kinda hairy given how easy it is to damage them. I knew a guy who's cat cut through some of the ribbon with it's claws. The cat lived, but was banned from that part of the house forever...

The material in the ribbon tweeter is incredibly delicate. When taking a tour of the Magnepan facility I got a chance to "play" with the thin, aluminum ribbon material. The people that work there are artisans.

Congrats on the rebuild
They can be very frustrating as you experienced
I was replacing the speaker protection in my Meridian DSP 6000(thermistor). Restoring the boards after delicate soldering a screwdriver fell across the v large power supply caps.
Big splash, expletives and back to the factory for a new board.....
Roger
PS what amps for the Apogees
I needed Krell 250 for my Scintillas
They had enough energy to boil a bucket of water with bare ends from the amp!