Chairs by Arne Hovmand Olsen  

For what it is worth, the chairs are beech. I do not have solid information either way, but I would be quite surprised if the chairs were designed by AHO.

Hmm....they look a lot like a set of Swedish chairs that I restored awhile back, except mine had the original woven paper cord seats. Mine were beech except for the backrest, which was plywood with a teak (or afrormesia, I can't tell the difference) veneer. I have never seen them in an upholstered version but they're rare enough with paper cord seats and it looks like the way yours are upholstered, the marks would be covered. They are on the top side rail under the seat, which on yours is covered by the cambric dust cover, though it's torn on that one so maybe you can get in there and have a look. Mine were marked Made in Sweden 10K-90. I have never been able to find the manufacturer or designer (if anyone in particular).
The stretchers are the same, the profile of the legs at the top are the same, and what's odd about yours is that the seat frames have two side rails. I don't think this is very common for upholstered seats, at least not when the upholstery covers the bottom rail, too.

Nice memory Spanky!
They sure look like the same chair to me. Bet they were originally all corded, or at least the design only accounted for corded seats. I could not see the back material clearly enough in the pics, to realized that it was teak.
Now to figure out who designed (if anyone) and made the chairs...

Also, the webbing under the burlap is most likely rubber Pirelli webbing, not leather. It looks a lot like leather at first glance but if you look really closely you can see the the reinforcing fibers along the cut edges. Also, it gets brittle and starts cracking when it gets old, though I guess you could say the same thing about leather.
If it they are the same chair as the ones I restored, I think it's entirely possible that the manufacturer offered them with upholstery as well as the more common paper cord---but it's also possible that someone had them redone years ago, maybe when the owners changed their minds about the seats (like, decided they were uncomfortable, or the cord didn't go with their other things, or one of the kids spilled spahgetti sauce all over one---could be any number of things!)
Also, these chairs do pop up every once in awhile, often just one or two at a time, and I have never seen any attribution ever.

I was wondering why the upholstery went so far down on the sides... I think you nailed it Spanky.
I wouldn't think the factory would have offered these with upholstery. I've just never seen this double rail design with an upholstery option. The design is specifically intended for one specific way of weaving danish cord. This makes me think they were re-upholstered fairly long ago.