Gluing the back on (probably too much glue). The spreader is only loosely in position.
The strips of innertube and bungy cord wrapped around drywall screws did a great job of holding the joint tight and allowed complete access to the inside to do the cleanup.
Still some sanding to do, but very pleased so far:
I didn't feel ready for finishing the carving of the top braces, so pressed on with the neck instead. I thinned the blank down a bit before gluing the scarf joint.
After cleaning it up a bit:
I did order some threaded inserts to see how they would pan out for the neck attachment, but despite them being described as steel (two separate suppliers), when they turned up both lots were some sort of cast zinc.
I was concerned that the threads might get chewed up easily (I've damaged enough of them over the years) so I decided to stick with my plan from above, and drilled the holes for the vertical dowel and the securing screws. I needed to drill the dowel hole before routing the truss rod slot (because they intersect) but, in hindsight, it would have been better to delay drilling the screw holes until I could put the neck in position and mark through from the headblock.
I went around in circles trying to think of a clever way to cut the tenon (router, sliding mitre saw, etc.) but in the end I just used a dovetail saw for the shoulder cuts and the bandsaw for the cheek cuts. I aimed to angle the shoulders in slightly per the Cumpiano book.
One side is cleaner than the other - I guess I can put whatever time it would have taken me to build a router jig into finnessing the hand cut joint. Time will tell...
I wasn't keen on the headstock outline in the Grellier drawing, so doodled around and came up with something I was happier with that geve a slightly better string angle to the tuners.
The shape looked OK on the rosewood headplate blank inside a paper cut-out
So I cheated and used my little CNC to make a routing / drilling template out of 3mm ply
(There are a couple of sets of holes on the treble side as I was still toying with an asymmetric layout.)
I bandsawed a quick-and-dirty dummy headstock out of a piece of scrap 12mm ply to see how the tuning machines fitted and to check for clearance.
The symmetrical arrangement seems to fit fine - Decision made!
Just got to make the real one now!
Thanks for reading