I don't know anything about the Kenmores. If you are interested in a vintage machine, I recommend Singer 15-90 or 15-91 since they are easy to repair and parts can be found for them. There are numerous tutorials on repairing them yourself, all found on you-tube.
Treadles are wonderful to use for piecing and quilting. It is easy to learn to treadle too. So, I wouldn't rule them out. Some of the prettiest stitching that I have seen has come from vintage sewing machines, like the Singer 201.
Lots of luck hunting!