These are by Dondorf (my favourite manufacturer), and are patience cards #26. They're also known as Kinder Patience, because they feature children on them; they're particularly collectible because of this. Those of you with long memories may recall that I acquired a similar pack in February last year, the principal differences being that that one was rather grubbier and missing its joker.
There are other, more minor differences, particularly in print quality — this year's purchase is superior. The reason may be revealed by the company name as printed on the Jack of Clubs. Last year's said "B. Dondorf GmbH" and "Frankfurt a/M"; this year's says "B. DONDORF G.M.B.H." and "FRANKFURT A.M.". Patience cards #26 were manufactured between 1908 and 1920, with GmbH at the beginning and G.M.B.H. later, so this year's cards are probably the newer of the two; the fact its joker is in colour would support this (as earlier decks had monochrome jokers).
With packs over a hundred years old, a difference of at most a dozen years in age shouldn't really mean much. If the first one lived through World War I and the second one didn't, however, I guess that could be a factor.
It's a lovely deck, though!