BAR raises a very interesting point in thread 8. I mean........, what is a commercial bayonet? The UK Military spec is well known as it is fully described in the EMER and the parts list. BUT Sterling weren't asked to nor did they ever supply bayonets to the UK Military. We were knee deep in them! (Nor did they supply them to the NZ Military or Malayan military either, for the same reason.....). They supplied guns and accessories to whoever wanted them. If someone wanted bayonets, they'd supply them at the cheapest cost to themselves at the greatest profit from the purchaser. Sterling manufactured the pommel, bolt, nut and spring plus the grip screws and nuts and (relatively expensive for some reason) grips which were cut by the same people who made the Mk5/L34 tool boxes and front hand grip.
Maybe it was the cost of the wood grips, screws and nuts was the reason why they got Helix to make the later plastic grips that are described as 'commercial.