Nathan Dodd wrote:The intention was always to refinish the guitar as a 'black top' to hide many other minor scars to the top.
In a similar case i decided to make a filler in the shape of a "pseudo pickup" and leave the original color intact.
See this thread as an inspiration:
viewtopic.php?f=8&t=1652#p15182It actually covers the restauration of two guitars (Isanas). In the 2nd case i tried to push a sunken top out by heat and tension. But You really have to shape the wood. Just forcing it into shape by bars might lead to failure in the long run.
What would you do at this point? Would you backtrack, remove the new braces and patch and make an effort to reintroduce the original arch by creating stressed glue joints and new braces that compensate? Would you continue with the top in its existing shape?
As i do not have a picture of the top my answer can only be "probably".
Something else: the pickup hole will always be a weak point in the top, especially if it is close to the neck where the direction of the arc changes in a complicate manner so that the filling s not able to carry the forces.
So the braces need to be strong (=high, 3-4 cm) in this area in order to be able to carry the load all by themselves. This immediately will lead You to scallopped braces which are high only where they statically need to be and low everywhere else.
I should note that the 1st of the two guitars is still a bit weak; it looks as if i'll need to reinforce it a bit more.
Please let me also notice that the responsiveness of both guitars improved drastically after the repairs.
For further interest the guitar will be receiving new binding front and back and to the neck (currently no binding on the back and neck), corrected back bow to neck, repair of broken heel, from 10 to a 12 inch radius on the fret board, full refret, new hardware throughout, full refinish along with the repair of all indentations, small cracks and various holes and gouges that have been drilled and cut into it over the years. It really was a shambles! Down the line it may also receive a floating pickup off the fingerboard (which also has to be replaced)
My idea of doing such stuff is quite different: leave as much as possible of the old structure and look intact. The fingerboard can usually be used after refretting, and the finish will look a lot better after merely polishing it up with micro mesh (well, on the 1st Isana i filled some of the holes, tried to match the color with stain and covered this with NC lacquer).
Every old instrument has its history. And these marks display that and contribute to its character. So why hide them?