... for my '67 GTR. One of p/n #0142-1220 hex bolt "D" (LH side of seat), and one of 09511-145 (12X45) for the RH side of the seat. NOS, or very good used. Odd that the parts catalog lists two different sizes, since the frame mounts for the seat appear identical, as are the seat brackets. PM if you have a spare set. Thanks!