The lights are simple mechanisms, and if they are complete and unbroken (especially the globe) they can be put in working order fairly easily. Since they come (came) in many designs, that is where the real value lies, e.g. how well will it match the interior decor. A used one can be worth as much or more than a new one for that reason.
"Not all who are laundering are washed" say Bill & Heidi
'78 Excella 500,"The Silver Pullit". vacuum over hydraulic disc brakes, center bath, rear twin. '67 Travelall 1200 B 4X4 WBCCI 3737