These are patience cards, measuring 5cm by 3cm. They're number 104, manufactured by J. Muller & Son in Switzerland. They were sold as a twin pack, in their original individual boxes and original overall box. This is what attracted me to bid for them. None of the cards themselves were shown, just the packaging, so I figured few people would bid for them. As it happened, I was the only person to bid for them, so that was a win.
Muller are more widely known for their Swiss Costumes design, which was widely imitated across Europe. They didn't produce many other designs, so this one is somewhat unusual. The gilt edging, flimsy paper boxes, high-quality printing and the artwork are very reminiscent of Dondorf productions, but the joker is specific to Muller; it isn't an outsourced rebrand.
I don't know when these were manufactured. The World Web Playing Card Museum doesn't mention them. I know from what it says on the side of the box that they were manufactured in Schaffhausen, where the company moved in 1873. Manufacturing moved to larger premises at Neuhausen-on-Rhine Falls in 1898. So, that would date them 1873 to 1898, which is plausible. If I'd had to guess, I'd have gone with maybe the 1920s, though.
Whatever, they're lovely little cards, however old they are.