the signal stat blinker units are aftermarket, at least for the TF - I think there were optional turn signals earlier than the 55.2nd and they may have been the add-on type
with the 55 2nd, there's a turn sig option that is 'built in' to the top of the column, and the lights were in the parking lights, but the fender top lights were
an options for the big trucks - either units with a forward facing lens only, or one with lenses on both sides - the one with the arrows was aftermarket
Bill