Ag sized tractors that were sold in other countries are not usually any problem with parts or service here. Deere builds these tractors here in their own factories. The gray market yanmars are not usually the same as the John Deere versions, so it is impossible for Deere to supply the parts for those units since they didn't build them in the first place. The ag sized tractors are usually near identical to sold in america models with exception to things like different lights, and sometimes they are equipped with parking brakes and park. And sometimes they have different hitches. The only problem is sometimes determining which comparable US model is the same.
In answer to Benka's question about serial number prefixes, I don't think there is any difference. All tractors built in waterloo, whether for US or another country, the serial number starts with RW.