Hello all- just after a bit of info about these actually. I picked one up in excellent condition at the weekend, dated early 1980s, and with an original frame (interestingly stamped 'Karrimor' and the military arrow). I think they must be fairly rare these days, and i certainly can't find anything out about them on the internet. I'll get some pictures tonight hopefully and post them.
Essentially it consists an external olive green H-shaped frame (i.e not the usual clansman radio frame used in the SAS/Para and GS bergens), and the bergen is olive butyl nylon with a zip pocket, large front pocket (with zip and buckle closure), two side pockets with press studs to fold flat (like on the SAS bergen), and a large main compartment with a snow sleeve at the top. Straps (the wide 'anti chafe' straps) are attached to the bergen not the frame. There is room for skis to be slid down behind the side pockets (fastened by a strap above and below the pocket), and the frame extends someway below the pack, presumably for stowage of a sleeping bag.
Most of the above is pure observation, but i would love to see some pictures of them in action, hear peoples experience of them and understand how the back was set up....