This is a rather unusual production from Bristol Armour, who seem to have been a subsidiary of British Petroleum, operating out of Bristol, England. They were active during the 1980s and 90s but vanished before the turn of the century (so far as I understand - further information welcome!)
This specific helmet has a similar shape and form to other Bristol products (I have one, illustrated below for comparison and others can be seen here Composite Helmet, Ballistic helmets, Military helmets UNITED KINGDOM, UK HELMETS, BRITISH helmet, Kevlar helmet ) but it seems poorly made overall. The shell is thick and roughly made, note the strange ripple effect in the interior of the shell. The surface is rough overall, and it has a feel similar to a piece of (believe it or not) earthenware rather than a sophisticated ballistic plastic. It feels like a roof tile, in fact, and even has the same sort of dull ringing sound when tapped. Its actually hard to believe it really is plastic and not pottery, honestly.
The liner is even more amazing - its a very simple bowl made of expanded polystyrene, with a very simple and thin synthetic fabric liner. So far as I can see it wasn't even glued in - nothing to sophisticated as velcro here! It holds in by friction, alone. It's rubbish, really. The other Bristol actually has a very similar liner, but it seems to be made of a more flexible and durable polythene-like material. I haven't had it out, it seems like its actually glued in.
The chinstrap obviously has its central part missing - compare to the blue example which has a complete chinstrap rig.
The label may be hard to read in the photos because it is inside a sealed plastic envelope sewn to the liner; apart from the makers name and address it includes GRADE - 17 and SIZE - 3. There is also a long ITEM PART number which I won't bother to repeat here as I got no return from it after extensive websearching.
The helmet also appears to have had a rim, probably similar to that on the blue one, at some time. Long gone, along with the central chinstrap section.
Also worth mentioning - the 'brick' weighs a fairly hefty 1420g, and that's without a missing chinstrap section and its rim edge. That's actually more than a medium Mk6, and a *lot* more than the other Bristol I have, which is a distinct lightweight at 896g in complete state..
No date, though I would assume 1980s. Its a terrible piece of work really and its not surprising Bristol Armour is no more.
Information wanted, definately.
The shell with and without liner -
The liner and label -
For comparison, my other Bristol Armour helmet, with edging attached, and complete chinstrap (the shell is actually blue, even though it appears brown in some photographs)-