I honestly don't know what to expect. The neck will be mostly wenge, so it might balance well without even removing any material. Originally I was just gonna go ahead and cut out some chambers, but now I think the best approach will be to not glue anything up and test it out with it all doweled and taped together. Maybe just hog a little out of the back and then strap it on, see how it feels/balances and then repeat as necessary until it's right, or as good as it will get, then go ahead and glue it all up.
I honestly think I should not even worry about weight and just focus on balance. I mean, I chose to make it 90% wenge, so it was silly to even make weight a consideration. It should help that it's only a 4 string and the body is both small and thin. That's probably the best I can hope for. I'll be surprised and happy if it's under 9 lbs when done. That's what the 5 string weighs and it's manageable.