As said above, believe bought out by BenAir A/S and the sheds and their crews still operate out of either / both Inverness and RAF Kinloss as BenAir crew.
BenAir's ex HD Air sheds now competes with Loganair S340 Freighters. I think that BenAir also operates B1900s and Let410s from Inverness.
Also chasing freight is Highland Airways with their JS31s, again, Inverness based. It can be quite busy up here between about 0400 and 0600!!!
Pity:I would dearly love to have left the RAF to work for them!
I will never forget the fact that a BAC Express (became HD Air?) Training Captain took the trouble to write an entire A4 page of advice to me re TP FOs following an unsolicited CV application by me.
I am following his advice albeit I cannot afford to leave the RAF until age 55 now, but he seemed to hold out hope for a career change self-improver at even that age!!! Now I am 48.
Good luck.
PS If you ever get a job flying freight up here, please PM me - I could really do with a career change now!!!