I see you found a place to print that out for you already! That was fast.
If I may toss out a few ideas:
If you stay with the shorty neck how about shrinking the body by about an inch all the way around - it might scale better with the neck.
Or, find a full scale neck. When I built one of these, hence the plan, I decided that I would shift the neck back about 1/2" toward the bridge end as the reach to the first fret was kinda long on my first build.
The basses were thin - I believe about 1 1/4" thick so the chambering might not be needed.
Good luck