Taking a quick stab at it, I'd estimate the first deck is from the turn of the century, circa 1900, plus or minus. The rounded corners weren't as common until the 20th century, and neither were indices, but the early index designs were small much like this one.
The second deck looks slightly more contemporary - and is that gold ink on the backs? Probably made in the post-Great-War years and before the Black Friday stock market crash - roughly 1919-1929. Indices that large were uncommon on earlier decks, and gold ink was eschewed on most decks made during the Great Depression, when few people could afford to buy anything so fancy.
I'd say to try the World of Playing Cards website for more information. They'd know more about decks originating from Europe and would have more examples on hand - most of the people here have most of their deck knowledge focused on American brands and products. We know European decks a little, while they know them a lot.