A simple google search turned up many of the part numbers for the seat belts, dash pad, etc. But not all of them and the list didn't include the knee pads. It referenced this thread:
https://www.camaro6.com/forums/showt...php?p=10342535
Best shot to get the P/Ns will be to ask a dealer parts clerk to do a VIN# lookup. There's a VIN# here:
https://www.camaro6.com/forums/showthread.php?t=552553 But I'll put dollars on donuts that they're discontinued and unavailable from any official channel. So probably the easiest way to "buy" a set will be to order a standard set, take them to a local automotive upholsterer, and pay then a couple benjamins to recover them.
Good luck.