The crane is designed to be driven without dolly, you don't have to have one. In the us, most states make you get under 26,000lbs per axle. Here in the state of missouri, I have to get under 20,000pounds per axle for the bridge /dot laws, to keep from destroying the roads and bridges. If your road department/ road laws don't require you to meet a certain axle weight, I would run without dolly.
The rear axles are designed to handle the load without dolly, that said, if your roading it 500 miles (or way more- I don't know how far you have to go), you better have pretty good tires, and check inflation often and don't run too hard. They're running 40,000 lbs per axle on the rears, with the counterweight mounted on a 8x4 carrier. And with 44,000 total up front, you're pushing load rating on a 14.00r20 on both the front steers, and rear drive axles.
It would be nice to remove the counterweight at the port, and haul it on a separate truck, it would really lighten you up on the rear axles. Just the counterweight is 20,000lbs. You can remove the counterweight with the crane, and you could send a separate truck to carry it.
You can more easily purchase one that isn't set up for dolly, it will be cheaper to buy and to put on the boat (you pay by cubic space on the boat?) . Not a lot of the older tm cranes were set up for dolly from the factory.