I'd like to help but that's like answering how much a 70' long ship weighs with 42 people on board and no fuel. Nevertheless...I'm just drinking my morning coffee so here goes....
If it's a complete tractor minus the engine? Just look to see what a complete tractor weighs on tractordata or in the manual and estimate the weight of the engine alone. If it's for shipping purposes, or to figure out if the trailer has enough capacity to hold it, then it's time to take chances.
In that case, take just the pulling rig and trailer and weigh it at a CAT scale at a truck stop, or a co-op, or a salvage yard that has a drive over scale. Load it up, and repeat at the same scale. The difference is very close to what it weighs (fuel consumption weight is a variable). Just weigh it with the same people in the truck both times.
I looked up the 3208 weight...899 kilograms..=just under a ton. And the weight of a 2255 (# of driven wheels uncertain) @ 16500 lbs
1650 - 2000 = 1450lbs maybe. Four wheel drive might add that 2000lbs back into the equation, I can't tell.
Lots of variables on that tractor concerning weights. There where three different rear tire sizes, front wheel assist with two different tire sizes, two different engines over the years,and so forth.
I'd say 15,000lbs without an engine would be a safe guess, but I might be way off too.