Thanks, Ty. Yes, I've found and bookmarked that site and all other auction sites I could find that had a variation of the chair. The pine one is a bit odd, but your conjecture that it could be a prototype puts it in a different light. It does have the same backrest pivot hardware and brass anchor for the limit strap for the backrest. The tight grain on the legs looks like old-growth, so it definitely could be an early version.
