Like Levi I also own a Talk Thunder 3.1b. I had to dismantle the transport to replace the laser pickup. It was not too difficult. I actually had to perform the disassembly twice because the replacement laser pickup was soldered (shorted) to avoid electrostatic discharge damage.
Yes, the mechanisms are plastic and fairly cheap. There are better mechanisms as Josh mentioned. I prefer what Naim and others have done. A drawer is manually opened and the disc is secured with a weight or magnet. I believe Sony, Rega and others use this as well.
I have an old manual in .pdf format for a Sony transport. If you send me a PM with an e-maill address, I'll be happy to send it.
Jim