There are shops online that stock old IBM spares, they can be very costly though. I'll try find the shop.
I suggest you find the T42 service manual, then you'll get part numbers for spares which you can use to confirm that it's the correct part.
I have an old Thinkpad 390E (P2 333mhz, 192mb ram) that I'm going to use as a gateway, the hinges are completely broken, the only thing holding the screen to the body is the screen's data ribbon cable, and Thinkpad hinges are STRONG. The rest of the notebook is fine though.