Knoll Bertoia's Authentic or Not
So I have a chance to purchase a trio and this is what I know: The seller states that they are quite heavy, weighing around 30-40 lbs (estimation, they are from the 50's, and some of the welds on the back needed to be worked on. Now to what I do not know: Are these chairs suppose to weigh that much (estimation) and are they known to need parts welded?

Here are the pictures and be blessed, Lenox

its authentic
Those chairs were too difficult for imposters to make. The only company that did had a base that criss-crossed. In the last 10-15 years there have been chinese and turkish plagiarists who use the same base design as Knoll, but the dimensions of the chair are wrong.

Lenox...
I have a pair of chairs in yellow and I bought a pair of naugahyde seats from the eamesbikini people (knowing that they're not real Knoll), and even though they were cheap, they were not particularly the right color or quality.

during the seni-annual Knoll sale, I bought a pair of real Knoll naugahyde seat cushions and they're brighter and beautifully comfortable.

Buy offical Knoll pads and your butt will thank you.

great
When the seller mentioned that the pads were "leather with sand," I immediately thought the same. That is, Naugahyde with broken down foam that could potentially be mistaken as gritty or sand like in quality. Thank you