Walnut and cane folding chairs... not the ubiquitous ones: any thoughts on origin?  

I've emailed Studio Schalling and asked if they can share how they made the attribution.
leif, the cane work is beautiful. I'll take some pictures of it later today for you. Mine is, sadly, wrecked and I'll have to get it redone. That's one of the reasons I want to be certain of the designer/maker. If they are not terribly valuable, I may attempt re-caning myself and not worry about them being perfect. If they are rare/valuable, I'll probably pay a pro to do it... although since the cane is double-sided on both halves, I'm sure it is going to be very expensive! Either way, we're likely to keep them for ourselves for a while at least. But if they are really rare and/or valuable (and I realize SS's pricing is quite high: it looks to be at least double what I'd consider fair retail value for the other pieces they have on their site that I've had myself or seen sold in the States) then I'd want to have the cane professionally done, I think, so they will retain their value.

I've seen a couple of Danish manufacturer marks/labels on inside seat rails that were hidden by upholstery, cording, caning, etc, including a Mogens Kold label. So when you (or your caner) removes the old stuff, keep an eye out for markings.
On a related note, I took a closer look at the SS listing photos/description and am confused at to what type of chair this is. Is the framing fixed, folding, or two-part interlocking? I don't see the pivot hinges anywhere and there is a SS photo that shows one chair in two pieces.
I like the design.

The chair is made of two pieces that simply slip together. No folding, no mechanisms at all. It's very cool. They are very solid to sit on, yet simply slip apart into two sections.

Nice. So I'm guessing that bottom rail extension for the backrest is integral to the chair support design. Looking forward to seeing more photos.

Many of the Mogens Kold metal tags that I have seen are affixed over the top of cane. So in this case I would be pretty surprised to discover a completely hidden Mogens Kold tag inside the cane.
Mogens Kold also seems not to have been very reliable about marking their product. This may be exacerbated by putting the tag over cane, so when a piece gets re-caned, it is all to easy to leave the tag off.