If you really need a accurate weight on that tractor you need to take it to a scale.
The times I have checked weights on tractors those weights and any correlation to the book bore no resemblance with each other.
For starters the weights on the owners manual and dealer book were usually dry and no aftermarket attachements. Fluids on a 2470 would be substantial. 100 gallons of Diesal is over 700 lbs alone.
Just no good way to get a accurate weight without running your tractor over a scale.