Bob,
LeBaron was a custom body company that was well known in the era and whose
work was found on cars of the rich and famous. Chrysler was a major
customer of LeBaron's and eventually gained the rights to that name.
As far as the "Impala" hood ornament - that was only available on the
Super-Sport, or SS model. I jest! You'll see this Gazelle on all the
Imperial CG's.
John