These cards were produced by Ferdinand Piatnik & Sons in Vienna c. 1900. The maker's logo and a tax stamp are on the Seven of Bells. On the King of Leaves and Ober of Hearts is a sign of the engraver: JN / 1880 (for J. Neumayer).
The cards were marketed as 'Doppeldeutsche', and the pattern is one of the Tell patterns (Tell 4 pattern). This example has German and Hungarian legends on the Deuces and German names on the Obers and Unters.
The special thing about this pack is that it has Sixes (last row below), with the Six of Bells as a 'Weli', a special card similar to a Joker used in some Austrian games.