Knoll Tulip Chairs. Vintage? Age?  

they are original
you bet they a re original ... The labels have changed from time to time .
Knoll international was formed in 1951 as a result of a United States state Department request to make furniture for American personal stationed overseas.
When they started making furniture overseas they had gone global with 21 overseas offices showrooms,and many licensees selling knoll products .
Knoll associates was formed in 1947,The associates and Knoll International labels were both used for were used for over 25 years .
Knoll studio labels came in to play in 1988.

crazy joe
your chairs are at least 45 years old crazy joe

thnx LRF — woow 45 years. Tha...
thnx LRF — woow 45 years. That's quite an age. Still look contemporary tough.

That is what you would call ...
That is what you would call timeless design and the genius of Eero Saarinen
That man died way too young (50) he was a brilliant furniture designer and architect. and a shinny star for Knoll.

c 1965
I have a couple of Knoll utlips dated 1965. I've replaced the cushions and touched up the Rilsan chips but the swivel is smooth as glass and I use them 8 hours a day in my office and have for 20 years. I took the seats off the swivel once to re-grease the axle. The mechanism in these is amazingly heavy duty, I doubt any of the knock offs use anything even close. I wonder what the current knoll tulips look like when you take them apart?

There's nothing like an...
There's nothing like an original! I was fortunate enough to score an original oval tulip table with the oval (cast iron) base.I nearly killed myself moving that 200 pound chunk of metal up the back stairs!Built like a tank to last for generations.Apparently,the newer versions are cast aluminum and made in Italy.