Some of the clubs are worn on the club symbol itself, and have been recoloured-in. It's not accidental wearing-out, either; here's a picture of the Ace of Clubs, alongside the Ace of Hearts (which has lines drawn on it as if to demonstrate that the heart is not central):
That pattern round the Ace of Clubs is drawn, rather than printed, too. I'll come back to this shortly...
The most interesting card is the Jack of Clubs. Here it is:
It has the same worn club-symbol, but has a name intriguingly written on it. Here they are in close-up:
It looks like it says "Grefle" and "Greffle". I've no idea why it would say that; "grefle", which I think is French for hail (the weather) but it could also be a surname or something for all I know.
The word "cercles" means it's a gambling pack (from "cercle de jeux" — circle of games, ie. gambling club). It might be that this could help date the cards more accurately, but I don't know the subject well enough for it to be of much use to me.
Now the interesting thing is that French playing cards often name the people on the face cards. The King of Spades is David, for example, and the Queen of Spades is Pallas. The Jack of Spades is ... Hogier! The Jack of Clubs is Lancelot. So what's happened here is that the Jack of Spades has been converted into the Jack of Clubs by erasing some of the ink and adding some more. Presumably, the same fate befell the Ace of Spades, which has been converted into an Ace of Clubs (complete with artistic attempt to draw the embellishment that the original Ace of Spades might have had). Whether this was necessary because the cards were manufactured so badly they came with two copies of two cards at the expense of two other cards, or because the deck was damaged in some way, who knows? Perhaps "Grefle" is an explanation as to what has happened to the Jack of Clubs?
It's always interesting when something has a story behind it. It might be a little more interesting if I knew what the story was, though...