The engine is from 1980 so the tractor is likely 1980 or 1981 if that is the original engine to the tractor.
The model no./serial no. that you listed for the tractor appears to be from a grass catcher instead of the tractor. The tractor model no. should be 1690516 if it has a hydrostatic transmission or 1690655 if it's a 6-speed.
The model no./serial no. that you listed for the tractor appears to be from a grass catcher instead of the tractor. The tractor model no. should be 1690516 if it has a hydrostatic transmission or 1690655 if it's a 6-speed.