I saw this Lefaucheux actioned double with hare's ear hammers on Simpsons yesterday. They claim it has no definitive makers marks or proofs other than two "crowns". I know Husqvarna used crown marks as a proof on their shotguns. But it looks to me to be a Germanic gun given the extensive use of horn and possibly even something from Joh. Springer? I'm just speculating, but either way its a lovely gun. Perhaps someone from this forum purchased it and can provide pictures and more information to solve the mystery...
https://www.simpsonltd.com/products/z38143