I'm sort'a late to the party but here's the pix with my best try at more contrast...... (Click the photo to get a big'un.) There are some good guesses out there But then, if you save the photo file to your computer, it tells you that the name of the file is "Petaluma main Street".
The 52 Merc is pulling away from the Singer store and the newest car 55 Buick is in front of the Drugs Store sign. If the Buick is band new it could be taken in 54.
What I find interesting is that the amount of traffic. Even though I didn’t recognize it as Petaluma, I went through the town the last time in the mid90’s. I don’t recall so much traffic. Lol.
The Merc is a 52 53 and 54 the side trim was full length the Ford is a 53 52 and 54 had the park light in the grill bar.