Well, the emblem is called a "fleur-de-lis".
Corvette is known for using this sort of flower in their logo, but not by itself.
Still searching.
EDIT: Should have refreshed before posting.
Is it possible that this was an aftermarket addition, rather than a from-factory emblem?
Because I'm simply not seeing it.
http://www.signselectric.co.uk/work/car%20logo%20history.html