Any of the below, & others, offered the stepped lock variant:
Karoly Kiszela Pesten - Pukar
Anton Vincenz Lebeda Prag
Anton Mulacz Wien - Bchsenmacher
Jozsef Kirner, Jr. Pesten - Pukar
Karol L. Werlik Teschen/Cieszynie - Rusznikarz
Antoni Werlik
Karol Spiegel Teschen/Cieszynie - Rusznikarz
I would guess he sourced Kirner or Lebeda, maybe Mulacz.
If you divorce the tubeset from the frame, marks there, if any, may point to the actual maker. Johann Hnl/Haenel of Willomitz/Vilmov more than likely was a Country Gunsmith that was more or a retailer/firearms merchant than a maker.
Steve is your Anton Vincenz Lebeda example cased and in the high 85xx serial number range?
Kind Regards,
Raimey
rse