Someone [with the original photo] could easily get the tag number and I’m sure the DMV could find the owner of the vehicle which you have the make/model.... the boys in the picture could still be alive ... plus there are the clues of “Ellie & Herb” ...not as difficult as one would think.
I would bet those DMV records are long gone. Depends on the policy of the agency concerning retention of records, but here is one example - the Department of Labor requires Injury Compensation files to be retained for thirty years after the last recorded activity on the claim. After that point, the records may be destroyed.