I agree with deadringer. It's certainly not an Explorer III for the lack of P90s, and not a Explorer 425 from that same year since those had a HSS configuration. As to the spec, deadringer seems to be pretty much on the money with that - perhaps save for the Kahler being a Gibson stamped one, since the flat-mounts of the era were straight on Kahler Flyers. In terms of the sale value, depending on the state of lacquer, abundance of dents and dings, I'd say somewhere between USD 450 - 700.
Any way you slice it, it's a great guitar - the Flyer is easily replaceable with a modern Kahler Hybrid and all you need to do then is to stick a locknut (NOT after-the-nut stringlock) on it, and Bob's yer uncle.
