Removing soiling from fabric.  

Haha, you don't have to be...
Haha, you don't have to be diplomatic. I know how absurd and tacky it sounded. We have two cats, and one is a Siamese who has claws and loves to ruin rugs, and to be honest I have been hesitant to get fabric covered shells for this reason.
We also have 15 foot windows in our loft, and try as we might, light does get in. I know it is a grandmother thing to do, but I did not mean as an all the time thing, just while I am away during the day ( an no one is there to see them) , as I cannot watch the cats or control the sun. I am possibly willing to forego my pride ( I am a shoe designer by trade, so I promise the idea even mad me shudder at first with visions of my Italian grandmother covering couches with plastic ) to ensure my Girards stay cat claw free.
As much as I love our cat Yohji .... I mean look at him, you know he is up to something.

I thought
of Mark immediately when that jacket was posted . . . !
I wouldn't object at all to "down-time" slipcovers. Seems like an excellent solution to day-time sun and/or pet activity. When you're home, off they come -- or at least when visitors/photo crews are expected !
Lovely chairs. I'm green (or orange/magenta/purple) with envy.
Mark, I want your cat -- at least temporarily, for a serious belly-rub/vicious-clawfight session. I'll forward my postal address . . .
Johji's next in the rota !

Oh Yohji is gorgeous!
and my dear SDR, You are most welcome to borrow Mr. Chopper anytime. He is extremely people friendly, but not real smart. I'd be quite surprised if he could learn how to rub your belly. But who knows?
As always,
Mark

Of course I have another...
Of course I have another annoying question.
So it appears one of the threaded mounts (on the 3rd generation mounts they only used the hand cut rubber washer with bolts into the shell) is missing from one of my chairs.
Obviously I don't want to sit in it if there are only 3 mounts intact , as I get nervous they will crack the shell as it is... never a fan of this way of attaching the base as it is.
Short of buying and parting out a beat late gen padded shell, are there any places that sell replacements for this part? I know it is a long shot as most of the stuff I see is earlier parts, but thought it could not hurt to ask.
Thanks as always.

Josh, there are many different
styles of metal threaded inserts available. Since you have access only to the underside, you'll probably need to redrill the hole in the shell and epoxy in the most appropriate replacement.
Can you post close-ups of the bottom of the chair showing both the damaged and original inserts?

Sorry for not responding sooner
I have been traveling for work and just got all the chairs this past weekend.
The formula suggested has been working. I have done it 3 times on each chair and so far so good. There a some seat stains that seem to be more than the oil from sitting, so that might be a bit harder.
The main issue is still the missing screw threading, and it seems there are 3 more that need to be secured as they are able to be pushed in and are loose.
Is this common to the 3rd generation mounts? I honestly prefer the shock mounts. But despite that the shells themselves are in excellent shape. Bases need a nice polish. I will keep the original bases on them but La Fonda bases would look really great on these.
I will post pics tonight of the shells in progress and the parts in question. Thanks for all the help so far 😉
Thanks again.

Glad to hear that you've had some success
with the stains and that I've not led you completely astray. I'm not sure what to do about the stubborn stains beyond trying the same technique with a stronger detergent like "Dawn". There's always taking them to the car wash, dousing them with "Simple Green", and blasting them with the 3200psi stream from a pressure washer, too.
Of course, this is an anonymous online forum and the advice offered here is worth exactly what it cost. That also means that apologies are totally unnecessary!
Those stripped-out and loose threaded inserts are going to be near impossible to fix satisfactorily from the underside. This may sound a bit daunting, but I'd think about just leaving them in place and gluing on proper shock mounts instead.

So here are the four I have,...
So here are the four I have, and it is hard to photograph at night but the majority of the arm oils is gone. 😉 Now as to the other issues.
The threads are not stripped, it is just that the brasses are loose in some of the openings in the base. When you push on them slightly they push inward, leading me to think they are a bit loose in the shell openings. I don't think it is more of an issue than glue but I could be wrong. They fit and are steady on the bases when put together but I am neurotic and worry about fiberglass cracking from uneven pressure.
Now the final issue is this very small cut in the seat on one of the chairs...is there any fabric adhesive that wont discolor or melt the foam if I try to glue it down? I would shudder to think someone would get caught on this and tear a hole in the seat. I am sure this is not an uncommon issue.
The cut is like someone had an uncapped xacto blade in their pocket ( which I have done myself in the past 😉 )
Slow going, but getting there. Now I need to sell my Burke set and get a nice Knoll Tulip to put these around. I ended up buying a 5th one as a side chair which I may consider putting on a rocker base. Would have been nice to get all 6. ;-(

Here is the missing brass
As you can see, the right one is missing. the others are there but like I said some are able to be pushed in leading me to think they might need gluing at the contact point between metal insert and fiberglass.

I think the inserts were friction-fit
originally and that they have a flange on the top side similar to what I would call a "T-nut". If you look closely, I think you'll notice that the outside diameters of the visible portion of the nuts have raised ribs designed to keep them from turning in the holes through the shells. I'm not aware of any epoxy capable of fixing this condition beyond temporarily and, obviously, there is no way to remove the nuts without first removing the upholstery.
As I wrote above, attaching new shock mounts to the chairs seems like it might be the best approach for long-term use.
*spanky* or others may be able to address the fabric repair. I draw the line at needles and thread.

Actually as i look at it, it...
Actually as I look at it, it does not seem to matter that much that the threads are loose in the shell, as once you put the screws in they pull downward through the hole all the way and the flanges prevent it from coming out of the shell. as long as you don't tighten too hard to put stress on the shell, seems to be ok.
So maybe short of the missing one there is no issue using them. I have one bolted up and it is pretty stable and sturdy. 😉
Fingers crossed.

I did buy a 5th one as a...
I did buy a 5th one as a back up, just in case.
As it would look odd to have 5 chairs around a table this one might get a rocker base and be an accent chair to the others.

I have
a couple of nice pics of Mrs. GA modeling that jacket prior to the auction. And even one of her seated on a compact sofa done in the same fabric. If she were less shy, I would post them.