Ed:
It's a Belgian double built, per the Perron and inspector's mark of "*E" on the watertable, on the Casimir Lefaucheaux system, possibly with a lockup mechanism based on Frenchman Brun's 1850 patent, peddled by German firearms merchant, and possible gunsmith, H. Friese in Northeim, Germany -
http://en.wikipedia.org/wiki/Northeim . Very typical of the period and pretty much the same design/model for pinfires which lead to central-fire. The "WR3"?? beside the "1504" might yield a clue it that is what it is. Just a guess but probably made between 1877 & 1890 and you are going to have to measure to get the difference for the choke.
Kind Regards,
Raimey
rse
