My Mom has a picture of me wearing similar duds, along with similar holstered "six shooter" standing in front of a similar vintage car. A '53 Pontiac to be exact, green 4-door V-8. Like this, only green.
We had that car from the time it was new until we bought a '62 Ford Galaxy Wagon, with bigger V-8.
Your ‘53 would have had a straight eight. Pontiac didn’t introduce their V8 until 1955 along with Chevy.