The style is called tub chair - I assume there are no labels either on the underside of the chair or cushion. To me, the style of the legs do not look like 60's - if you google retro black tub swivel chair you will see the difference. They certainly made very similar things in the 1980's. I am no expert in retro furniture, and they may be something special. But I see second hand chairs that look like this struggle to make $15 - 20 in B&M auctions. Condition looks good. Good luck if you decide to sell.
