Do rear taillights with backup lights from -57 fairlane fit on a -57 custom 300 ?
yes
yes but you need the whole assembly ( of course including the back up light bulb sockets) including the Fairlaine chrome bezels.
because of the back up lights the bezels on these have cut outs to increase the red taillight area. the std non back up bezel is solid and will not allow light to the outer reflector ring.