The transmission and hydraulics--basically from the flywheel back--is an IH B-414, 424, 444, etc. From Tractodata, it looks like the engines, etc. are 100% British. (The 424 and 444 built for the US market used front axle, sheet metal, and gasoline engines at Louisville.)
Should be a good tractor, my only concern would be parts availability. I don't know anything about older, small British gas and diesel engines as far as parts availability goes. Check the hydraulic system carefully, some parts and especially people that know how to work on them are getting scarce. The hydraulics on these tractors are very tricky to work on.
Edit: Mahindra built clones of these tractors for a while. It's possible a good Mahindra dealer could source parts NLA from caseIH.
Al