antique gibson guitar

I have an antique electric guitar and I know nothing about it, can anyone give me some info?
It was my grandfather’s and it is in perfect working condition, however, there’s no company name on it anywhere. Someone told me once that is was shaped like a Gibson, but obviously its not, otherwise it would say Gibson on it. The only thing on it is a small butterfly inlaid in abalone on the head of the guitar. Does anyone know anything about it?
Apparently it’s an old Japanese knock-off from the ’70s. Check this out:
http://ask.metafilter.com/61966/What-is-this-guitar
METAL MIKE June 22 2009 Junkman Antique Gibson f Hole Guitar