Not sure, I had a 62' but it is gone, seats were different than say a 69 for sure. You might try the FJ25 owners group, I see some early FJ40 conversations on there. I still have a 1963' FJ45 SWB but I did not get seats with it, I put in a...
Early lines were formally clear plastic, as said at glass fuel filter and to tank. I don’t know what the thread is tho, I changed mine a lone time ago (not ethanol resistant either!).
Bob in CO