Modern swivel chair identification  

I don't know what they are but I like the look of them.  They're definitely vintage with that 4 prong base (OSHA requires five now so that you are less likely to tip over---or is that only on furniture made expressly for the workplace?)
I would redo them in a texturey solid without those seams on the inside back.  Those seams bug me.  They interrupt that nice flowing curve. 
I think the price is very good unless you can't live with that upholstery and would have to pay a few hundred each to get them redone, then you might want them to be of some note design-wise, I guess.  Maybe.

I think they will be gone before you can get there at that price.  

Thanks for the quick replies I don't have a need for them but since there still available and he has 3 I just emailed him and asked what he would do on a set. 

How much do you think they are worth if $75 seems high?  Maybe let someone else enjoy them for that bargain... 
 
Sorry, i don't know who designed them either...