Rebuild: Update 2

I began work on adjusting the neck tenon to achieve a proper neck angle. This was accomplished by manufacturing a precise wooden shim to place on the back side of the neck tenon. For the shim, I needed to use a hardwood to preserve the rigidity of the mortise/tenon connection. Since the tenon is mahogany and the mortise is maple, I would assume to use one of these. I chose to use some left over maple veneer for the shim. It was already thicknessed to 1/16", so all I'd need to do is taper a small piece that is profiled to the shape of the tenon. I did so against some sandpaper.

Maple shim tapered from 1/16" to 0", ~3" long.

To assure the shim brought the neck angle to the proper position, I loosely placed it under the tenon and used a C clamp to hold the neck in the mortise. I strung the high and low E strings to observe the action. Here's my setup:

C clamp temporary setup

The shim will need final shaping to assure the tenon and mortise sitting flush. Otherwise, the neck angle seems perfect. The bridge sits a little high, but I assume after applying full string tension, the neck will pull forward slightly and I can lower the bridge just a bit. It isn't hilariously high. Below are some pics.

Down neck view with new neck angle and action. Looking good so far.

The string elevation looks much better. The string angle from the bridge to the stopbar should apply more pressure to the body, increasing sustain and tone while reducing buzz at the bridge. 

Next step is to glue the shim to the tenon, use graphite coated paper to find high spots on the shim. After leveling the shim, I will tidy up the surrounding neck surfaces around the joint. It will be ready for gluing. Before this, however, I'll need to strip the finish and do binding work.

Updates soon.

-Mr. B