For all practical purposes that looks like a Jinma tractor all right. A lot like my 2006 284, only bigger with more stylized hood and fenders. Jinma made tractors for a lot of different "brands" and there were differences between all of them but the base tractor was the same. Jinma made their own up through the 500 series that indeed were listed at 65 HP.
The 630 on the loader decal is just the number of the loader. Is there a number on the hood decal? In the pictures of both sides it is blocked from the view by the loader arms. Even so it may not be much use because the name KJT is not listed here:
List of Tractors built by Jinma for other companies
Of more importance would be a data plate on the tractor itself. Usually there is one riveted to the inside of the fender. I can see a spot on the right fender near the rear where there may have been a data plate at one time, or it might have been something else mounted there. On my 284 it is on the left fender near where the toolbox is mounted, although I can't see a toolbox on this one. There may be a bracket in that area.
The casting date of 2006 is interesting, where was that located, on the engine? In any case, it is just a casting date. Of more importance is the data plate of the engine. A lot of times these are on the block but in many cases they are on the valve cover, usually on the left side. If you can't find that, then some of the information cast into the block may or may not be of some help.
As for the pump all the information about it should have been on a data plate or at least a sticker on the pump. That would have told you everything you needed. Did your friend take a picture of the pump before he took it to the "mechanic"? Loosing someone else's property is the height of unprofessional and boarders on theft in my book.
At any rate, all is not lost, just more difficult. You can measure the bolt pattern where the pump mounts. Then you can determine what was on the drive end of the pump. Was it a gear, at tab or some other design. Then you can measure from the mounting face to the point where the pump engages the drive. You want to be as accurate as possible with your measurements. Use metric. If possible watch the drive gear and turn the engine with a wrench in the direction it normally runs. What way does the drive turn?
This much info should narrow the search greatly. There may be other things like pump size and adapters needed to get to the hose fittings left on the tractor.
Affordable (listed above) and Circle G both have good online parts diagrams that you can browse through. They also have a lot of pictures of the parts themselves. Some time spent there looking around might show something that you or the owner recognize.
Let us know if you have any questions and by all means post more pictures of anything you think might be a clue.
Good luck and don't forget to post the final resolution when you get one, it will help others in the future.