Platner Arm Chairs- help with refinishing questions  

Ooh, these look great in aged bronze finish, IMO. Not the most comfy, though, if I recall. Is there a DWR or Knoll showroom near you? Seems like either could supply new cushions or, if either has one on the floor, you could inspect in person.

I live in Boise, ID so we have limited resources for designer stuff. I contacted the Knoll dealer in town to ask for any recommendations on who could help restore my chairs. They didn't know of anyone. 🙁 I also contacted Knoll directly and left a voicemail with someone but have not heard back. I talked to a local reupholster and in her 40 years of reupholstering she had never work with chairs like these.

The other thing you also need to look at is which upholstery version is it, partial or full? Your frames look like the wider ones with full upholstery. You can go to the Knoll site for that and google some images to look at. Knoll and the Knoll dealer probably will be more helpful if you ask if you can buy replacement upholstery from them if they are available and if not, you need to widen your search to the nearest big city like Seattle for a re-upholsterer that have worked on Platner chairs but whichever way you choose, the replacement upholstery will be costly. Good Luck.
And also these chairs will look great with plain weave solid color fabrics (Knolltextiles) unless you are the adventurous type, then go for a vintage Jack Lenor Larsen with a psychedelic swirly pattern, but it is all up to you.

Based off the measurements they are the partial arm chair. I am planning on sticking with a solid color. I really like the turquoise fabric as seen in the picture below 😉

Knoll definitely sells fabric retail though that doesn't mean that the people in that department will necessarily know the specifics of how these chairs are upholstered.
I just looked at Platner chairs on 1stDibs, which in my opinion is the best source for clear closeups of details. I found a bunch of chairs with these small clips along the top edge of the fabric in back. I have not reupholstered a Platner chair but I've done some others that had metal rods inside to help shape padding----guessing maybe that's what's going on here? But I really don't know. I don't think it would be all that hard to redo so that it looks correct, only because it's basically two pieces of fabric and some padding.
I also found examples that did not have any visible clips, but I think they may all be newer chairs. The ones on Knoll's site do not have visible clips, for instance.
If you do a google search for 'reupholster Platner chair' you will find a few places that advertise their services specifically for this chair, plus some old DA threads with at least one reference. There is also BK Upholstery outside of Philadelphia, if you want to ship them that far. I couldn't find anything about the actual structure and technique involved but I also didn't look too deeply.

Yup,
My old chair has clips. There is some sort of molded (fiberglass?) shell that the upholstery adheres to prior to being clipped onto the wire frame....I think.
Best,
Aunt Mark
ps I'm usually mis-imformed.

Yup.

yes, you should use a Knoll textile. And a proper vintage woolen one, not one of their more recently concocted ones. It is going to cost a fortune to have the redone right, so it will hardly add anything to impeccable choice in fabric.

Ooo, thanks, Mark! Mystery solved!
I see Knoll currently offers these with their "Circa" fabric, which is a low-nap chenille. It's a good quality fabric but it's definitely not vintage. The gold metal line can also be ordered with Knoll "Velvet", a classic mohair pile. I'd go with that before Circa any day. Some of their other archival wools have always seemed rather lightweight to me as far as durability. Cato is gorgeous but probably too bulky to work well around the radii of the molds---if you decide to get them fabricated.

'Cato' by KnollTextile, a classic and in continuous production since 1961 and it is a wool blend..currently at $162/linear yard with a minimum order plus shipping. You need to find a copy of the book "KnollTextiles" to get to know the names of the period correct upholstery and if they are still being produced.
https://www.knoll.com/knolltextileproductdetail/Cato
You need to "friend" a KnollTextile rep...it helps like in these chairs, you do not need a lot of yardage.

Hi.
1.8 yardage for the side chair.
Hi,
Aunt Mark

Also, keep an eye on Modern-Fabrics.com and Ebay---Knoll regularly sells off their mill ends to third parties who then resell them, often at below wholesale prices. The less yardage you need, the greater your chances of finding something you like.
The bigger problem is obviously the fiberglass liner things. I wonder if there's a substitute material that would work, that would be easier to fabricate? It would be a totally reversible fix, should the real parts ever pop up.

OK Sweetie, un-asked advice from Aunt Mark.
Do consider leaving the chairs alone. Possibly repurpose one chair frame as a "catch all" in the foyer (things like wet coats, car keys, firewood, etc) and load the other chair with cool toss pillows and a pet cat. Restoration would be too expensive. Plus, the beauty of the chair is in the perfectly spaced welding. Show it off. Call it art. Tell two friends.
Respectfully, but with hands on hips,
Aunt Mark

I greatly appreciate the fabric suggestions. It's hard to know the quality of the fabric without talking to someone who knows and the ability to touch!