There is a major difference between a model "never originally intended for sale in (insert your country here)" and one that was only ever intended for sale in a certain specific market like the ISJ machines.
In the case of the former you walk into your local friendly Cat dealer, quote the Serial Number, and they will sell you anything you ask for because all parts & service information regarding the machine is clearly visible on their system.
In the case of the latter (which are classed as true grey market) the look you will get when you quote the S/N to the guy on the parts counter is somewhat akin to what you'd get if you had grown a second head (©
@willie59), because no English information ever existed for them. It is all only available in Japanese.