My older Husqvarna top lever hammer doubles (1890 to 1922) have very minimal marking on either barrels or receiver -- nothing like the clutter of stampings one sees on German doubles, or even the later Husqvarnas. A model #, serial production # and assembler's initials are often all there is.
My emerging understanding of Husqvarna hammer doubles is that precise dimensions of receivers depended on supplier (or production run?), with barrels, locks and stocks fitted as needed. I seldom hear of someone being able to easily fit one set of barrels to receiver from another gun of same model -- and this has been my personal experience as well.
Niklas
