Trying to identify and find a little info before I buy. Any help would be appreciated.
I think that's an early Terratrac dozer made by the American Tractor Company. Later bought out by Case.
https://classicdozers.wordpress.com/dozer-gallery/case-terratrac/
They weren't a bad machine, they use the same Clark transmission as the OC-3. They have a Continental flat head engine.
The sprocket mounting on the final shaft is often a problem, there's a nut that gets loose and the splines get worn.