I'm not sure ballast matters if your tires aren't getting traction. Do they make R14's for your size tractor? Even R4's would be an upgrade over Turf Tires. Turf Tires are specialty tires, IMHO.
When I read 'Snow Tires' I assumed you meant Turf Tires. I don' tknow if they'd be any good at all working the dirt. And you don't want to mess with putting the R1's back on. Can't say I blame you for that one.
You could always spring for the rims and tires you want/need and sell your existing setup.
Just spit-balling, that's all. Feel free to ignore me