Re: Trying to find a value.
The problem will be the lack of a known brand-name. Most music stores and guitar 'on-sellers' will want to know that. Any instrument of unknown manufacture are usually considered to be virtually worthless, regardless of quality because there is no point of reference. Even many expensive, custom-built instruments from individual builders, that cost the original owner thousands of dollars, will barely be worth the cost of the parts if the original owner decides to sell it.
(Conversely, something like a hacked, heavily-modded, beaten-to-death Ibanez, Gibson or anything with a visible brand logo can be valued as there is at least a reference point).
The only exceptions are when a player simply takes it for what it is, decides they love it, and are prepared to pay a reasonable sum for it. Even then, such potential buyers will be aware that should they ever want to sell it, they too will be faced with the same issues.
Perhaps the way forward is to try to discern what brand it is, possibly by dismantling it and inspecting for internal clues. There may be websites/ forums that specialise in older, wackier instruments who could view a couple of pics and give you some clues.
