Panton chair?  

Hi everyoneI'm looking for some more information about three possible original Panton chairs. Two pictures of one of them are below. Do you think this chair is original, what is the possible edition or manufacturing date and what is it worth?I've already read this website: Panton-Chair - Verner Panton and found this information:1971-1979the third series model made of coloured thermoplastic polystyrene (Luran S). The chairs made of this material can be identified by the ridges below the bend between the seating area and the base.Manufacturer: Vitra; in the USA until 1975 Herman MillerThe Panton Chair was not in production from 1979 to 1983. 1983 to present daysecond version of the chair made of painted polyurethane rigid foam. This series can be identified by Panton's signature on the base.Manufacturer: 1983-1990 Horn on behalf of the WK Group; since 1990 Vitra; since 1999 this model has been marketed under the name Panton Chair Classic. My chair has the ridges from the 1971-1979 period and doesn't have the Panton's signature on the base from the 1983 to present day... What would be your conclusion?Thanks for any help! greetingsNick