Some of those pics have to be real or at least partially real (those with vegetation in the background).
I think that's the whole point. He constructs models of old cars and storefronts and photoshops them into actual current-day pictures of the town. The result makes it look like he stepped into a time machine with a modern camera and went back to around 1952.
Imagine if you could go back to 1952 as a 20 year old, knowing what you know now...
It’s a matter of perspective and focal length and depth of field. Look at pics 4 & 5. 4 shows his table with model, set up out in a snowy back yard. Notice the paint brush at the top right corner of the table. Now image the camera at that level, with the film plane aligned with the line of the brush, and the artist standing at the diagonal corner.
The artist and the trees behind him are real, everything else sits on the card table.
Very cool work, and so detail oriented; it’d drive me to drink. I wouldn’t have that kind of patience.
He places the camera so that you see real landscape and sky in the distance. Only the foreground buildings and cars are models.