I have a very rare SBG2-6 (red SG) made by Martin/Sigma from 1974. It's in kept in it's original HSC and played very little. The original pick-ups have been removed and Seymour Duncan's (I believe) have been put in. It's in great shape for how old it is. It does have a few nicks on it, but overall I'd give it an 8 out of 10. I've searched online and asked many people from musicians to pro's about this, and no one has any info on it.
It plays like a dream and sounds even better!!!
Any info that I can get or how much it's worth would be awesome!! I would be willing to part with it if the offer is what I'm thinking it's worth.
ANY HELP IS GREATLY APPRECIATED!!!