Are you sure the serial number isn't SPL2618? That would make a bit more sense. Guns marked SPL are custom order long barreled guns. Guns marked SPC are custom order short barreled guns. Unfortunately, neither prefix gun can be accurately dated, unless one of the Bruchets remember the individual gun-don't laugh, they usually can.
The Darne works did on occasion produce live pigeon guns. They tend to be older, and less common than the light game gun configuration, but, they exist. Most of them have very heavy wall barrels, and a few have the pigeon style rib, which is very wide, and flat. I've never seen one in the states, but, have handled a few in Europe, and procured one from France for a friend. That particular gun is quite unique, as it features an R11 frame with full coverage foiliate engraving, the heavy barrels, wide rib, no safety, and a weight of about 9 lbs. It was built in 1901. Neat.
A few pictures, of the barrel flats and the name as it appears on the opening lever would sure help.
Best,
Ted
