Knoll tulip chairs  

Today I got 7 tulip chairs for free. They are in varying stages of disrepair.
Two have armrests and each has a very faded Knoll sticker and a second sticker in green saying gnw1786. They are all white and very chalky. The other 5 don't have arm rest and have blue bases with white seats. No labels. Some of the bases are de laminating and some have rough spots on the edge of the chairs. The bases are aluminum. As they sit on my carport I am wondering if there is any way to rehab these. They have been sitting in a barn for many years and have lots of oxidation. When I wiped off the grime and pigeon shit the chalky residue keeps coming off. Any ideas as to the rehab or should I give them up to Craig's List??

Now that I have cleaned them up I can see the two labels on the armchairs are 'Knoll Associates' Looks like '800 Park av,
New York, New York'. Super faded, but still legible. The armless chairs are stamped 'br51' on the base. I have no idea regarding how to go about repairing. I'v taken pics and will post (still struggling with transferring photos) soon. I did have a look at the Knoll time line trying to glean when they actually went from Assoc. to International.