I've got a 2010 LR4 @187k with the same vacuum pump leak. Planning on ordering the rebuild kit from Amazon, if anyone has had any luck with it. I'm guessing oil needs to be drained for this.
Klifex Vacuum Pump Rebuild Kit for Land Rover Discovery LR4 Range Rover LR010690
https://www.amazon.com/dp/B09J2PX2QF/ref=cm_sw_r_apan_glt_i_331H5E8BT45HXF8BKX8W
I've also noticed the upper right (passenger) timing cover seems to be leaking pretty bad. It looks easy to remove, just need to pull the larger coolant line. Doesn't appear to anything mounted to it or need valve cover removed. Anyone know if there's a gasket for the cover, I could find one. The plan is to remove, clean and use RTV.