1, No, different bearings than a 1/2 ton
2a, Not sure about dust/grease seals
2b, There were for a short time tapered roller bearing kits for the 3/4 and 1 ton offered by one or a few of the restoration parts vendors. These bearings were non standard size, seemingly made for this one application, the part numbers on the bearings did not cross to anything else available. They were Chinese bearings. Best I can tell no longer available, unless you commission your own production run of special bearings.
3, No, the original type bearings are adequate.
