You are correct it is a 76 model. This bike has more in common with the YZC than the 74 YZ. The tank is steel and a small amount larger than the alloy YZC tank, same shape though. The motor has a steel bore instead of chrome and the carb is a 30mm compared to the bigger YZ carb. Fenders are the same as the YZC. They all interchange. With the Curnutts on the rear I am right at 8" of rear wheel travel which is more than the YZC.
I think this one of the prettiest Yamaha's from the period. It has just great lines. I searched for one of these for 35 years.