to Raimey:
Imperial eagle:
My DGJ articles (Court suppliers summer 2006, Springer summer 1997)
had images of imperial eagles ; first from a poster ex museum shop of the imperial mansion in Bad Ischl, the second from a box-cover ex
Springer. Both show a similar/equal central element like this one here.
Kalezky serial numbers should be found on the trigger tang where
one holds the stock.
Number 2051 could fit as I did guess for 1900.
(But have seen Kalezky pair and single without any serial nr. at all).
Felix Neuberger