Mr. Chair Help  

Cant tell you mcuh
Plycraft constantly evolved the form of their plywood chairs, all stemming from their copies of the Eames Lounge and Ottoman. I've almost never seen two chairs that are exactly alike.
This one was most likely designed by George Mulhauser. It looks like a later extension of Mr. Chair - the headrest has been brought forward and is more unified with the backrest. Mulhauser was an important, if little known, designer who created many chairs for Plycraft. His Plycraft signature is usually the bent-wood base of the chairs.
He also designed chairs for George Nelson & Associates, most notably the Coconut Chair.