No 3

[John Parchem]

I would struggle at this point on my own guitars how to go forward. A martin bridge are often 11/32" So you are a 16th thinner. You may be OK 12 mm (15/32") is a reasonable SS string height. With 5/16" plus (6/32") 2 * action of 3/32" minus 3/64 (string tension) puts you very close to 15/32".

Redoing everything in metric as working with fractions is nutty.
8 mm + 5 (2 x action) - 1 mm = 12mm

So with the thinner bridge I think you can keep what you have. One thought I would consider is just a touch of fallaway,the fretboard slightly lifted from the top, would give you a bit more margin. I like a bit of fallaway anyway as the neck pulls forward under string tension. The fallaway helps the extension not turn into a ski ramp. I finished my 3rd guitar with projection height very close to yours but with a more typical bridge. The straight edge did not clear the bridge. I was able to set it up with an OK action but within 5 years it need a neck reset as the action was too high and I did not have anymore saddle.

I know Ken never thought you needed to glue the extension as string tension and the neck moving forward held it down, but he missed that gluing the extension down helped lock the neck to the top and the heel block. The fretboard is a very important structural brace not gluing the extension down weakens the guitar in a very vulnerable place.

[Paul C]

Ok John thank you.