To add further confusion, the lid style on the old "pre 1969" 26ers were originally rounded and gradually transitioned to the flat top lids between 1965 and 1968. Meaning rounded, then kind of "in between" rounded and flat top then finally flat top with the twist on ash pan. 26er ash pans were Wood Dale era hold overs with the U cut-outs and the swivel clips until about 1967-68 or so.