If you need a part number for your Jeep (wrangler, cherokee, grand cherokee), go to the Tech Reference on
http://http://www.xjjeeps.com and download the parts catalogue for your year. It includes LHD and RHD, petrol and diesel. (requires acrobat)
In this case, the clutch parts are specified on diagram 6-330B (page 108 of 1045). Master cylinder part number for a 2.5 diesel is 5210 7703. A new reservoir cap 4741 671 would probably be wise too.
Edit: rally_man, please check the part number against the diagram, don't want you ordering the wrong part.