I have a foot exactly like this. I got my first sewing machine in 1950, a Singer treadle machine to which I later had an electric motor added. I don't think the zig-zag machine had yet appeared on the market then but this foot did and was advertised in some small magazine and I ordered it. I used this all the time and thought I was very advanced - I found it very easy to attach and use.
Zig-zag machines came later. I still have this foot but of course it has long since been retired.