Selig chair  

The shape of the top of the arm looks familiar to me but the side of the seat frame is not at all familiar. I'm reposting your photo rotated to upright (dunno why some get flipped when posting--possibly something to do with how you had the camera oriented when taking the shot.)

If you could include more photos of just the frame, that might help, and some closeups of details like wood grain, joints, types of fasteners, etc. The cushions look like they might be replacements so they don't matter so much. If you can move the chair into better light, that will help too.

I'm especially curious to see what kind of webbing is on there (though it might have been replaced too).

Thank you so much, Spanky! A few new photos attached. The webbing on the seat is completely missing.

How are those back springs attached to the frame? Threaded ends and sockets? It appears to be the same material as the loop springs (experspring, etc), but I don't believe I've seen them used in a non-loop before.

The arms and leg frames are very similar to well-documented designs by Kofod Larsen, but the seating boomerang frame is an anomaly.

Thank you for your reply! Here's a picture of the springs attached to the frame.