Per the Banc D'Epreuves Des Armes a Feu De Liege (Proof House for Firearms of Liege)
https://books.google.com/books?id=5fxGAQAAMAAJ&pg=PA52&lpg
First Obligatory Proof Load for Double-Barreled Breech-Loading Sporting Guns - 12g breech plugged "rough forged" tubes
21 grams = 324 grains = 11.8 Drams powder and 32 grams = 1.12 oz. shot would/should have received the script EL



It is my opinion (which means little) that "rough forged tubes" for export were very lightly stamped to facilitate filing the mark during joining and finishing. It did occasionally make it through the process however; a Lefever push opener



Tube maker's marks seemed to have been much more deeply struck

"JDH' on another Lefever



and it was common for the U.S. makers to over-stamp the maker's mark

Smith with Armor Steel over LLH of Laurent Lochet-Habran



Smith with Crown over LLH & what is left of ?ACL Acier Cockerill Liege



AND there are a bunch of presumed importer marks which I have yet to ID; RIS & Co



SO the 'LP', 'WJ', and ? 'HB' could be a Belgian tube maker, Belgian exporter, English importer, whoever joined and finished the barrels, an English distributor or small dealer, etc.

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