All I can say is it's almost exactly like mine, except mine has no sunburst finish, the pickguard is more rounded, the headstock is black with a different "Harmony" logo on it (more swashy). Binding looks slightly different, especially round the soundhole. There's no label in mine and the serial number is all but unreadable. It looks like 418681200 maybe. It has a natural finish, loks to be mahogany back sides and neck. The tuners aren't original; they were replaced at some point with Grover "step-sided" machines off an archtop. Two screws through the bridge, which uses what looks to be a piece of heavy fret wire for a saddle. It was dropped at some point for there's a split along the top lower bout and the binding is cracked. And the top finish shows a lot of tiny cracks all over from temperature change, but that looks really cool on it against the natural honey-like finish. You can't see the cracks until you tilt it at an angle to the light.

So it needs a bit of work but I picked it up pretty cheap at a flea market. I'll get it into real service one day.