Mogensen Style Shell Chairs  

I acquired these today and was wondering if anyone could help with an ID.  The bases are teak, or maybe oak,  and the backrests are bent plywood.  I've only found one other example so far being sold by a London shop and identified as "similar to Mogensen" but unidentified.  The front and back stretchers appear to have mortise and tenon joints, but they do not extend through the legs the way Mogensen shell chairs do.  I'm assuming they are not by Mogensen but would like to figure out who made them if possible.  Thanks