Aye it's leased out, most of there game shooting is leased out now too apart from some of Drumlanrig.
Used to be a lad on each estate that done the stalking as well as other estate jobs, think still inhouse on langholm (last i heard a few months ago) and possibly bowhill.
Possibly the estate office could put u intouch with the 3rd party that may lease the stalking, i know stuart has a big chunk if not all the game shooting on bowhill now, no idea if he has the stalking too