date this bertoia? need some help please  

Date
A clue would be in the postal code. The 6 letter/number combo started in 1972.

thank you rosewood!
i thought of the same thing, googled it but couldn't find! appreciate it.

Valuation
In my opinion, older Diamond chairs are not necessarily significantly more valuable (monetarily speaking).

That's a
very acceptable textile on your diamond, phonegirl. I think that I might have a sport coat that would match.
Aunt Mark

thanks fellas!
yes, i'm going to try and buy the chair. could get a bit complicated because the seller and I may not agree on price but I'm going to take a good look tonight. I was thinking of you all (Woody, Eameshead, Solange, Aunt Mark et al) because I *think* and *hope* I bought a pretty decent sofa. I was feeling sheepish about some of the stuff I posted. I was so impressed by the quality of stuff you guys find. I'll post pics now! Hope you're all well!

phonegirl
Look out for broken wires, separated welds, etc. Best of luck to you.

Hi
First off its a small...
Hi
First off its a small diamond chair, and nice, but more common than the model 422 wide diamond. I love the wide diamond, as they have a more loungy seating position, and are more roomy and cozy.
There is no good reason to date it from the cover label, unless you know the original owner of the chair and the cover. I have a new cover on my very early small diamond. My original, old cover is in the basement.
The more important thing is no broken wires! Hey- if one breaks, the remaining unbroken ones will get more load to carry, and then they break. Next thing, you have a visual only chair, just for looking at. I just saw a rusty hunk (bird chair with no shock mounts) go on ebay for 450, and was shocked. Its shocking that people don't look these over closer. The seller claimed it was comfortable! Hah!
Another case on ebay is a wide diamond, with broken wires in numerous places. It would be 100-150 for someone to repair, and the bidding starts at 350. I wouldn't dream of setting on a broken one, now that I have repaired 10 or more.
So woody is right, condition of the wires is more important than age. There are ways to date age, but its specific to really early, a long span of sameness, and then maybe you can tell if its really new or not. The wires are thinner on really older ones, and they break easier. You need calipers to measure the wire, and I won't bore you with diameters. Its only .03 - .04" of an inch less on the older ones.
You are actually better off with newer versions, and the thicker wires. Unless you are slender, then its not so important. My ebay tracking over the last 12 years says that the value goes in waves or trends anyway. Lately the value on all small diamonds is suffering due to Chinese versions coming into the market. There are way more small diamond copies, than wide diamond or birds. In fact, I have yet to see a wide diamond from the land of China. The repro bird is a real joke and isn't having an impact.
Don

thanks!
I suspect the chair came out of the same house as my newly acquired sofa. it made it's way onto the floor at the thrift shop at the exact same moment. I totally understand what you're saying about a new cover on an older chair. it's absolutely in perfect condition with the full cover (will post a better picture - i bought it). the chair will look really nice in the same room as my sofa so i'm happy. the welds are all good. Fair price I think at $400. Regardless, I'm buying it from a friend who grabbed it while I was at work. Thanks for your thoughtful comments.

My opinion
Newer production chairs have notably thicker wires and thus do not have the same aesthetic appeal.
I'm sure they are much more durable though.
$400 is a fair market price for a vintage Diamond chair in excellent condition with full cover.

thanks ww.
will post some photos when I get the chair on Sunday. I personally haven't found a darn thing this week but a friend found an incredible Tapio Wirkkala bowl. BIG. sculptural. Can't stop thinking about it. I, have a problem 😉

oh! question...
wwood, can you define "newer" chair?

phonegirl
It's difficult to pin down exactly when Knoll makes/made changes to the designs. I would guess that anything made after 2000 would have the thicker wires, but it may have even been well before then.
Yours looks to be vintage. Not early generation, but somewhere in between.

again, thanks
wwood! my guess was late 70s, early 80s. will post photos regardless, just for fun! and hope to god, no one yells "fake"! 🙂

ok, here it is...
i think i put the cushion on upside down.
also, the hooks on the cord - anyone tell me are those just hooked onto a wire?
it's waaaay cleaner than i remembered - like, almost brand new. like, mostly likely brand new, like fake? thoughts?