Plycraft"Bernardo" / Cherner-esque chair  

I have a pair of chairs that have a Plycraft label under the seat. The shape is very much like the Cherner/Bernardo, but in all my searching of the web I have not seen chairs that are fully upholstered like mine are , with the zipper up the back. Though the bottoms are clearly wood, I have been afraid to unsip the zippers for fear of damaging the covers. Anyone know what the story on the covered up version is? - My hunch is it was a cheaper, lower end product.

Where can I find out more about these vinyl covered Plycraft cahirs ?
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