i loved making this and its relatively simple.
heres an idea of how i made it
First thing I did was cut the front and back shapes.
Then measured the sides and cut suit.
Are used 3 mm ply for this.
Next I glued all the sides to the back leaving the front off and left them to dry.
wood glue or gripfill will be suitable
Cut it 50 mm wide 30 mm thick and 900 mm long. Leave one end 100 mm² for the headstock.
Cut the 3 mm Length of the top of neck by putting the top of the base on it.
Now offer the neck up to the back side of the box. Mark and cut the front side so It sits down flush. Set it in place and screw the back.
Get a hardwood strip the same width as the neck to the length you want and glue also.
I bent a piece of brass and screwed to back to pick up the strings.
Drill a suitable hole inside for the jack and stick the other end on the underside of the bridge.