I would attach a strong string securely to the disconnected end under the dash and pull out just enough to see if there is a disconnect near the lamp. Hard to believe they would hardwire the light but it was 1956 so...If not then you could install one and then carefully feed the wire back under the dash using the string to assist. You might also consider this a good time to lengthen the wire to provide more slack in the future. Note I have a 49/3100 not a 56 but this is what I would do.


Ed