Franz Denk most likely was the firearms merchant here. He's sort of an obscure Austrian maker and usually didn't peddle any junk. I'm interested to see what Springer's Erben has to offer as 5000 is considered pretty much when time began with Springer's Erben serialization and most give circa 1870. So if the serial number is less that 5k then it was made prior to 1870??? I'd guess it was made in the 1870s and the tubes steel looks to be cast or fluid steel. Any marks there? Also I've seen several doubles with that unique barrel latch with "ARVAUD Bte." I can't recall what the correct spelling is but check it with a glass. Maybe PeteM can recall. The device may have been a holdover from the pinfire era. I have a close-up image of the stamp somewhere and have been chasing that advancement as well as the number assigned to it on each weapon. It's a T handle, just pull it forward toward the muzzle and the tubes should release. He doesn't appear to taunt the K & K Kammer-Lieferanten title, which was awarded/purchased in 1872. Johann Springer was born in 1819 in Leutschau/Löcse, Hungary. In 1840 he caught a cart out to Vienna. So the weapon may have been made between 1870 & 1872/73.

I thought the 10.75X52R Springer Marine was developed toward the end of the 19th century? But a chamber cast and some measurements will reveal the cartridge.

Interesting soap opera on the Mathais Nowonty & Johann Springer relationship. More than likely, Johann Springer was an apprentice at Mathais Nowotny's shop. Mathais Nowotny was born in Leitmertz(Litomerice) in Bohemia. In 1838(1836??) he moved to Vienna and I bet Johann Springer was on his walkabout. In 1847 Johann Springer married the sister of Mathais Nowotny. Then in 1852 Springer leased Mathais Nowotny's shop, or some portion thereof, while Mathais Nowotny built a small weapons making facility and acquired the proper permits. Mathais Nowotny was a maker to one of the courts by this time. Some love triangle developed and Mathais Nowotny(Novotny) couldn't accept or deal with it, so he commited suicide in 1857. Shortly after the self inflicted mortal bullet wound, Mathais Nowotny's widow sold the business and the small weapons factory to brother-in-law Springer.

Kind Regards,