Doesn't look prototypish at all. To me it just looks like an early model. With the oval cream colored pickup.
And the output does not look original to me. I don't think Gibson used metal jackplates in those days. I think they always used plastic.
If it were an original with just one output, it wouldn't need to be so rectangular either.
The seller mentions the switch doesn't do much. Normally you would hear significant differences in sound. And of course you'd have the two outputs.
Which leads me to think the electronics have been messed up.
Price is a bit steep, yes.