In this article we will look at a few American companies who loaded pinfire cartridges. Von Lengerke & Detmold was a well-respected New York dealer of fine European-made sporting guns and fishing tackle. They were founded in 1882 and were sold to Abercrombie & Fitch in 1928. They had these pinfire shells custom made by Kynoch & Co. of Birmingham, United Kingdom, and then loaded them in the United States. They also sold their custom shells as new-primed empties
The firm of A. G. Genez was a manufacturer of high quality double barrel shotguns. They also made conversions on guns from earlier types of detonation forms, such as pinfire or percussion, to newer formats, such as centerfire. They also loaded and sold shotshells for their manufactured or converted breech-loading shotguns. The company was established by August G. Genez and spent most of its history at 9 Chambers Street. Genez operated there until November of 1880 when it was advertised as succeeded by Vincent Bissig.
A much more detailed article on A. G. Genez can be found here: