This card set is a Bavarian card deck. With numbers 5, 4, 3 and 2 added. Those are very uncommon for a Bavarian card deck, but were added so that all KDE games can be played with this deck. The cards are created by a small Qt C++ application, which will also be released under the GPL soon. The font used on the cards is called "Bayern" and is an old Bavarian font. The cards were mainly created for the upcoming game "SchafKopf" which needs a Bavarian card deck.
To install a carddeck, download the tarball and extract it to $HOME/.kde/share/apps/carddecks or to $KDEDIR/share/apps/carddecks. The carddeck should be available to all your KDE cardgames now.