Those numbers would indicate a VERY early pair, but is there also a number stamped into the "circle" cutout on the back where the inputs and dial are located? If they are that old I would not have expected them to come from the factory mirrored as that happened later in production (after serial #4,***-something I think?). If they have a Regnar upgrade and refoamed woofs then they've definitely been upgraded from original stock. Regardless, enjoy!! Post pics of everything.
SpongeSound