I recently ordered some replacement gears from here:
$8 for 12 parts + shipping
The design is opensource, you can find the 3d files here: https://www.thingiverse.com/thing:4167139
I have quite a few drives I'm replacing the gears in so I'll post my experiences here.
Replaced my first drive - an 800k external that was not ejecting. You can see the in the first picture the state of the old gear, it denigrates to the touch.
The fit is good, you can see the teeth line up well.
The video shows the first few ejects. Note the springs for the top were not attached when I took the video. Also the drive has some noise when spinning, unrelated to ejecting.
So far they seems to work just fine, I've done about 20 ejects and all feel the same. We'll see how it holds up and I'll post here with any updates.
Probably the best option will be to try to have a contact with Adam Goolevitch (Canada) who is the owner of one of the two Twiggy known units.
he was able to revive his own and the other one, has a lot of knowledge of Twiggy drives and Apple Lisas (1).
Has been there, done that...
probably a contact through Cult Of Mac i agree..
Finally I got Loctite 401 and glued the clip to the center cover. I left 24h before mounting and it looks very solid. It came in with a very satisfying click noise and stays in place properly.
I printed it with a 0.2mm nozzle and set layer height at 0.1mm to achieve better resolution.