Hi Steve,
I can’t make out the serial number in the photo, I don’t see it written in the description, and the Singer badge is missing (can see the holes where it HAD been), but it might even be a Centennial machine. I would say that the head, bench top, and treadle stand are all of different ages. That’s just my guess.
I have a 1951 Singer 31-15 (AK443567) Centennial that I’d like to get set up and running in my industrial treadle one of these days, but I just don’t have the room for it right now. We had a 1936 Singer 96-40 in the treadle stand for a while (I had rigged a small electric motor on it for her in the photo below), and my wife experimented with FMQ on it, but I took too long to find a suitable FM foot for it. That, plus we ran out of room for it in our home, and she decided to start sending her large quilts out to a friend with a Long Arm. She does her smaller quilts on a Singer 301A (was mine, now it’s hers, long story).
CD in Oklahoma