This has nothing to do with a CBG, but the situation I was dealing with and how I overcame it could be helpful to someone as far as building technique/solutions are concerned.
I acquired a set neck body for a SG type guitar on FB Marketplace for a good deal, finding a neck for it wasn't easy.
I had also acquired a Gibson scale bolt on neck for a cheap amount.
So I thought about adapting the bolt on neck to the set neck body. I was working on a set-neck SG kit and compared the 2 and decided that I'd make a "spacer" to glue in the neck pocket to bolt the neck onto or glue the neck to or both!
The spacer would have to have a degree cut of 4 degrees to give the neck the right tilt, but it would have to have the neck at the right height and the part in the neck pickup cavity would need to remain a certain thickness without interferring with the neck pickup height adjustment.
Using the kit set-neck to get all my adjustments and checking the bolt on neck measurements, then subtracting the last from the first, I was able to get the right measurements for the needed spacer. I made 4 spacers before I got it all correct and cut right. I used some Red Oak I had in my shop for strength and had to orientate the wood to ensure that I wouldn't be gluing or bolting into end grain.
The spacer at the body pickup cavity is 10mm thick, 12mm thick at the end of the neck past the 22nd fret and 5mm at the 17th fret where the spacer ends.
Total length of spacer is 115mm
Width is 57mm to fit the neck cavity tightly and happened to be right with the neck width.
I'll be attaching the spacer first and then the neck being careful to get it in it's right scale position, making sure it's high enough for strings to be in plane with the bridge and making sure the neck is straight so outer strings with have good spacing on the fretboard without dropping off.
This guitar has been a PITA! I've had a bunch of issues, but then I got some more. While pressing in the bridge post bushings,the body cracked from the bridge pickup cavity to the back end of the body. It's a thin crack, so fixing it isn't needed yet. I decided to wait and see if it opens up more before dealing with it.
I got it all together and put a couple strings on it and the neck angle is too much(4degrees). It looked right when I checked it with a straight edge. Looked at my straight edge and found that it had a slight bow in it. Did my Yosimite Sam impression. LOL
Now I have to route down to 3 degrees and recheck. Then more if needed.
I was building 2 guitars at once and both gave me trouble, but I finished one of them and I'll get this one finished too.
Done with this one for know. It needs touch up for the body paint, but I'm waiting to see if the body crack starts opening or not before painting. Either way it'll get fixed eventually.
The final degree for the neck on this ended up at 3 degrees. With a guitar that requires a angled neck, it's hard to say what degree it will need. I have 3 SG's now and they all have a different neck angle. One is 4, one is 3 and the other is 3.5. The best way to figure it out is by putting it together loosely clamped, adding the 2 outer strings and adjusting til it looks right. Then take measurements at the neck joint for the proper shim/angle.
This pickup combination has become my favorite: A5 P90 in the bridge and real A2 Firebird in the neck = Glorious Tone.