Johann Peterlongo was a mastercraftsman and firearms merchant from the the mid 1850s till 1898. I believe Jani has the whole story/rest of the story, but I think Johann Peterlongo founded Tiroler Waffenfabrik Peterlongo in 1854, when he was 28 years of age. If he was born in 1826 he should have been a master by say 1850 and depending on what he had going on in the 1850s, he could have hung out his shingle anytime from 1850 to 1854. Richard Mahrholdt seems to be a real interesting character and must have been an apprentice or spent most of his walkabout at the Johann Peterlongo compound seeing he was the manager from 1898, when the lone bell tolled for Johann Peterlongo, till 1918, which was about the time Mahrholdt founded his company. If I'm not mistaken he penned the Waffenlexikon editions 1931 & 1937 and being an authority on weapons continued to mound info until his death in 1949. His son Herbert, possible the und Sohn of Richard of Richard Mahrholdt und Sohn founded in 1919, took the reins and penned the subsequent versions like the 1957 version. Richard Mahrholdt was born in 1878 and would have been a master by 1892 or so. He may have worked a stint at the shop of August Schuler as sources give they were close friends and some of offerings by Tiroler Wafenfabrik Peterlongo had the odd Schuler cartridges.

Littlegun is one source: http://www.littlegun.info/arme%20autrichienne/ancien%20artisan/a%20peterlongo%20gb.htm

Your Peterlongo example has the Rigby style forend latch which was a favorite of the Vienna craftsmen but without a doubt it was sourced from Ferlach, a weapons production nexus centered around royal hunting grounds. I'd make a cast of the chamber before I purchased any brass. Polywad are great for target while RST will fill the bill for any game pursuit. Dig would attach some concern to the dent, but if it is 2/3rds the length of the tube I wouldn't worry with it until you have the longarm in for some additional work. Nifty little read fold-down sight. The not for ball stamp denotes choke. Any chance of a pic of the area from the lugs to the forend latch?

Kind Regards,

Raimey
rse