It seems that tubes wearing an encircled LB, or LB in an oval, are quite common in the 1920s. Maybe PeteM can comment, but it seems odd that there is a date stamp but also the bore in a rhombus? Anyway, so it is possible that the Lhermitte & Bruyninckx concern switch to sporting weapons, or in tandem, with their fishing components. Interesting that L. Ory, if the same Ory as partnered with Duquenne, dabbled in both fishing reels and sporting weapons:
http://www.littlegun.be/arme%20belge/artisans%20identifies%20no/a%20ory%20and%20duquenne%20gb.htm


http://www.littlegun.be/arme%20belge/art...yninck%20gb.htm
There was another LB, Lambert & Bruyninck, but it seems to have been LEB and sourced LB for tubes? Maybe at some point Bruyninck/Bruyninckx changed partners?

Kind Regards,

Raimey
rse