Lacquered plastic chairs Identification help  

I wanted to add a little bit to this.  I guess I am also looking for a more refined eye to give me an idea of wether I am on a wild goose chase.   Do these look like designer chairs. A few people have told me that they look like toilets, but I attribute that to my shitty photography skills.  In real life I think they resemble stylish bowling chairs more than anything. 
I find them fascinating, the creases or hard edges help the chair appear very different from different angles.  I often find myslef walking by them and thinking WOW they look cool from that angle. 
They don't have any stamps or makers marks.  There are no seams on the outside of the chairs.  The plasitic is shiny and glossy.  A local dealer told me that she could tell that they were from the 60's because that shinny smooth plastic was not used after the 60's, but I can't find anything online that wold ID the age based on plastic type. 
I have sent pictures to three auction houses, the first was a local one.  He said that since there were no Auction records for the chairs and no maker stamp "they were likely for the middle market", but I guess I find that hard to belive because if they were for the middle market they would be easy to find, right?  He gave a value of $300-$500 for the set. 
The second auction house said that while they didn't know the maker they would put an estimated price of $500-$700 and that it would likely go higher.  I told her I would continue to look for the designer and she  seemed genuinely interested in finding out who made them if I could find the designer.  
The third place (Rago) said "Sorry low auction value" . 
So at this point I think I want to keep them, so I am not worried about value as much as I would really like to know who designed or manufactured these chairs. I am no photography pro so they never look as good in my pictures as they do in real life. 
So basically give me your opinions please even if you don't have the slightest clue who made these. 
 
Thanks
Mike

Designer is Perttu Mentula, PMD-Design, from Finland. Late 60's

OMG thank you! I have been looking for sooo long. You are the best!!! I am so excited.  I can't find much about him right now, but I will look harder.  Thank you, thank you, thank you!