Kattare,
admittedly, not an outwardly cheap way to acquire the offending gear, but it really is an investment. I don't know of anyone who has conclusively found an exact match in any other device, and the KSS-162a and 220a (completes) don't have the same gearing that the TG-CD has. The gearing seems to be unique to this device, and one of the gears seems to have been made from a defective plastic.
I can understand if no one sees any pressing need to take this task on right now...and the only reason I'm not is due to financial and time restrictions. But that won't always be the case (knock on wood), and someday I will shell out the $80 or so to be able to make my own gears. My intention is, after a successful run, I will sell them to forum members for a reasonable price. But that's putting the cart before the horse. I just want to attack this common TG-CD problem and make it a thing of the past.
I would consider it a great honor to have such a large role in keeping the systems alive.