There are a few hickups in the serialnumer records, but it looks pretty clear on yours. It starts with 0 or O.
However, it all points to a 128 (the top tensioner and the high set bobbin winder). The earlier 28 has a manaul thread release lobe, the later 128 has thread release in the presser foot lifter. It's in very good condition, clean shiny and the decals are in great condition, even with the damange in the corner. Most machines are much more worn. The early Singers (early 1900 and before) often have much heavier hand wheels. Like you I wonder if it's an older machine fitted with motor, lights and upgrades later on?
Last edited by Mickey2; 04-27-2019 at 11:34 AM.