Thanks for posting the pictures. These early Prussian Daly hammerless guns are interesting, and the there is still quite a bit unknown about all their details. I have a hunch about the early hammerless Dalys that do not exhibit the Heinrich Lindner marks, but it is speculation so I hesitate to say much on these.
As Raimey points out, the APUNs are a interesting clue in putting the Daly timeline together. I own Charles Daly hammerless serial #7 ("Lucky #7") and its APUN is 65. With 11 serial numbers between Dalys #7 and #19, it is obvious, looking at the 59 number APUN delta between these two, that other makers besides the maker of these guns were taking advantage of the new and excellent A&D design - as you would expect.
FWIW, my estimate of your gun's manufacture date (late 1870s) is at the earlier end of the date range Raimey provided based on the patents and other Dalys noted in this range.
Ken
