I would venture to guess that Jim and Steve are correct, that this is a 1958. A rich kid friend of mine had one when I was kid and this looks identical. His WAS a 1958. We broke one of the rear directional covers and when his father went to the Honda shop they could only replace it with the directionals that protruded on a short post or tube. The original directionals were oval like, but the new replacements were round.
My bet is it's a 1958!
Wanna sell it? It was the year I was born!!!