Did all E-bodies have these inboard brackets/braces on the underside of the floor pans (see red circled areas in photos)? My '70 Challenger Convertible does not have them, but the outboard brackets/braces ARE there, and I believe the floor pans are original, but not 100% certain. If all E-bodies had them, does anyone know if these are being reproduced? Were the welded in? Thanks