Welcome to the Forum, Dale

,
I notice that you posted a link to listings of gunmakers marks of 'modern times' (XX century) and Richard's example dates back to a couple centuries before that, respective marks being found in different sources.
I am not a French speaker but, i would not get it how 'leconois', assuming this is the exact word engraved, would give a derivation to 'lesson' (in french
leçon) or that it would be relative to apprentice (in french
aprentis).
On the other hand, assuming these inscriptions are indeed French, their relation with the maker of this double barrel would not be coherent if such barrel is indeed Spanish, but that is something that remains to be established, as admitted by Richard.