I'm bound to ask just how far back can your eye be XL? It's got to be 2" or so from the ocular lens to get the full optical picture so based on the rifle above, that's putting your eye level with the rear of the bolt. That seems to be so unergonomic (is that a word?) on the head and neck while shooting as to be unreal.
The early alloy ocular focussing ring had a replaceable rubber insert that seemed to be made of a sort of plastercine! The later one on the tele shown on thread 1 was better.......but....... The housing it was on couldn't be fitted into the earlier telescopes!
I don't think the knurled thumbscrews v. allen bolts were an identifying feature per se. Just a matter of being ill informed if you were unwise enough to use allen bolts. That's because the mild steel thumb screws shafts were designed so that you only tighten to thumb/finger tightness otherwise they'd shear and not just strip the front thread. And if you give a crunchie the tools and wherewithall to overtighten something, then guess what he WILL do?
I was a paratrooper and for the life of me cannot see what allen bolt/1" diameter thumbwheel will do to affect parachuting techniques!
I can see where this is going but as a bloke from the bleedin' obvious school of life I feel that there might be a degree of urban myth creeping in here. AQnyone remember the horse manure surrounding the special black SAS and Marine lens caps......... Just a minute while I phone up Steve XXX one of the RM Armourers.............