Heathkit VC-2 Voltage Calibrator

I picked this up at OSU last winter, finally got around to checking it out a bit. I’m not really sure what this is specifically useful for. It outputs a square wave of a settable voltage. I’d love a scan of the manual as I haven’t found one on the internet. Benny the Beaver. The peak volts scale is obscured by a replacement graduated dial. Set up on the bench. 4.26V when set to 4V… 9.36V when set to 8. I’m guessing that the dial is not graduated correctly. Why is it there then? Who knows. An internal potentiometer. The internals are typically simple and beautiful for the age. Removed the aftermarket dial face. Have to give it to my friend Spud… With the dial removed it seems more accurate? Almost spot on…  Not so much at the .1V multipler, Nor at the 10x multipler at 1V(x10=10V) At 2Vx10 I get 22.6V, so there’s a pretty consistent extra 2.6~ volts. But at 5Vx10, I do get almost 50 volts.
I don’t think this was meant to be a precision reference, although I may be wrong. I could play with the internal potentiometer I suppose. Anyway, a neat thing.