I wouldn't expect other drivers nowadays to understand a flashing headlight bucket meant you were turning rather than about to burst into flames

seems like it wouldn't be very visible in daylight and not at all at night when the headlights were on
when I had a 37 Ford with that style lights I converted to a more modern setup with halogen bulbs in the headlight buckets and separate
lights for turn signals mounted on the bumper irons like fog lights .... I believe Chevs of the 40's would have some conversion options for upgrading the headlights to be more useful
Bill