I find it impossible to blend the the neck and bridge pickups on the SG because the volume pots for each pickup seems to work on the basis of giving you everything at 10 and nothing at 9 and below. Is this a characteristic of the pots or the pickups? If the pots, then what type of replacement pots do I need?
I have a post here with a similar problem. I re soldered all my grounds and it it behaving as expected now. http://www.talkbass.com/forum/f38/very-basic-i-think-wiring-problem-1003467/ btw I've played a few of those SG's and have been able to blend the PU's with no problem.
I don't think you have a pickup problem. I do a lot of blending on my SG with the volume pots down in the 3-5 range with no issues.