I dunno.........having been a Ford Street-Rodder in a past life, I remember 39 Ford tail lights being shorter and fatter than those on a Speedster, and the Speedster tail lights are segmented - there are actually two, separated lights in there, one for tail/Stop and another for directional (in fact, the European versions have amber directional segments toward the outside).
While it might be intriguing to update to LED technology, I think the Ford-style lights would maybe look too different, and you would lose th segmented functionality. some of it may be nostalgia, and some of it may just be a really cool "look", but I kinda LIKE those 356 style tail-lights!
George B: Bet'cha didn't think an "Outlaw" driver would be thinking like a purist, did'ja?.......gn!