Paul,
The 444 were built both in GB and the US. Main difference is the electrical, Lucas on the GB built ones and Delco on the us built ones. GB ones have a B as the beginning of the SN and US ones have a U. The 2444 is just industrial versions of AG tractors with foot throttle and HD adjustable front axle. Of course you can get the Low Boy version, with frame mounted back hoe, etc... Parts for the 2444 are not an issue can be picked up at CNH dealer. My loader is a 2050.
Ben