I've got a back seat from a 1983 245 that I'm trying to put in a 1974 145. The seat back pins are a little bit different; (My father and I spent a few hours today finding that out the hard way.) the 145's got a solid pin on one side and a pin that pushes inward on the other while the 245's got two slightly shorter pins with wide heads that push out. They attach to slightly different mechanisms on the body, as well. Anybody done this swap and have any tips (IE, can you swap the 140 pins into the 245 seat) as to how to go about doing it? And if not, what year did they switch the mechanism to the newer style? Could I put the 1983 back seat in a 1975-1980 era 245 (I know '81 uses the same wide-head style as the 83), if I got one?