Discovery help! LH drive export; looking for parts!

Hi all,
We are renovating a property in Slovenia and its rather remote. I needed a 4x4 to get up an unused lane and move big logs etc. I purchased a Disco locally which did really well for a while, until i lent it to the builder to bring materials up. He lost drive on the road near the house and its been in the garage for 6 months until i get back out there with some spares.
The local mechanic is confident its the mid diff in the transfer box as it still drives in diff lock.
My documentation shows:
DISCOVERY 200TDI
2.5L MANUAL DIESEL

Chassis number translates to 1998 build yet first reg is late 1997.
I have been told by landrover the part number for a transfer box is: STC 8959
Also, I cant work out which gearbox I have. Am i right in saying it cant truly be a 200TDI as its a 1998?
If yes then do I need a R380 or LT77 gearbox? I only mention this as I have see entire gearboxes plus transfer box attached at a very reasonable price. So it would be easier to just swap the lot.

Any help would be greatly appreciated.
I only have the chassis number as the foreign reg plate is no help.

Thanks much!

Will

CHASSIS NUMBER:
SALLJGMF8WA750854

Some other stuff under Slovenian headings:
LJD5 - 71V
83KW

1998 would be a 300Tdi, makes no odds as transfer box is the same on both, is he 100% it's transfer box? Not front diff or a blown CV/snapped half shaft? Basically, has he stripped it down or just put it in diff lock an tried it? No point taking home spare transfer box if the front half shaft has snapped.