It was the precursor to the Touch & Sew (or "Cuss & Throw") machines.
They're pretty solid slant-needle machines, much like the Rocketeer, with some extra features. If I remember correctly, any model number before 628 is all-metal innards - somewhere around that model, Singer switched to plastic gears and the fill-in-place bobbin.
My mother-in-law had one and she was terrible on her machines - it had been non-functional for a while when she let me take it and refurb it - I spent days cleaning the old 3-in-1 out of it and got it sewing perfectly again. Gave her a bottle of TriFlow to use, instead.
She kept complaining that she couldn't get it to sew, but every time I tried it, it worked just great. She swore I "broke" her machine. Maybe she just wanted to buy a new one, I dunno. 😄