It won't fit in the truck whole?
My thoughts on this (
and trust me I have no idea what I'm talking about). If the bed of the truck is long enough what I would do is first remove that heavy chuck from the lathe. Remove the tailstock. Run the table up as close to the head stock as it will go and lock it down. If you do leave the tailstock on the lathe also run it up as close to the headstock as possible too and lock it down as well.
Then put the lathe on the truck with the headstock to the front of the bed so that all the weight is just behind the cab in the center of the truck.
Then strap it to the corners of the bed so it can't fall over.
I'm not sure I understand what's to be gained by removing the lathe from the cabinet? How are you going to fit both pieces in the bed of the truck? Would they fit side-by-side? Is so you could certainly do that way.
The lathe should detach from the cabinet quite easily.
In any case, whatever you do best of luck!
Another quick suggestion just cause I thought of it. You could drive down without a trailer, and then get a U-haul trailer for the return trip. That way you would only need to tow the trailer one-way.
Anyway, good luck with the move!
If it's close to my house I'll go pick it up for you. But then you might have a hard time getting it back from me.
That's once nice lathe I think. I like those older models. That's back when they made things for real. It's worth driving 1000 miles to pick it up IMHO.