Oh yeah, the tape in that last shot is to hold the straight edge in place, darn near impossible to do when a camera is occupying one of my two hands..
Now secure the neck whatever method you choose, I run a wood screw through one of the tuner holes into the workbench after I have pressed the heel into a neck pocket and pulled it tight.
Now, I recommend taking a marker, and coloring each fret… this makes seeing what you are doing much easier… and you can fine tune you truss rod leveling…..
Place your leveling tool on the fingerboard and give it a shove, remove and check the marked frets… it the end frets have been scraped and the middle ones not, then tighten the truss rod a touch and repeat. Continue until the frets toward the center of the fingerboard are being “hit” too. Now re-coat all the frets with the marker, and recheck. If the majority of the frets show exposed metal from the fret leveling tool, you are ready to rock.
Now using your fret leveling tool.. oh… here’s how to make one……. Use any good flat material…. Corian is great, but plexi-glass (1/2 inch thick) works or MDF… cut you a strip about 2” wide by about 18” long….. then cut a second similar strip… glue, screw, or whatever it to the first in a “T” configuration. This makes it rigid. Now check it with something of known flatness. A cast Iron table saw table is perfect, but a piece of glass on a flat surface works too. Using spray glue, 3M-77 is what I use, glue a sheet of sand paper to the flat surface, now take the “T” shaped tool you have made, and run the working surface across the sandpaper until the entire surface has been sanded. That’s flat enough. Now using the 3M-77 glue a strip of something like 180 grit wet or dry paper to the tool and you are ready.
Now begin scrubbing the frets…. I use relatively short circular strokes allowing the tool to roll with the fingerboard radius. You will see the tops of the frets being exposed.
My tool is a machined piece of steel, with 180 grit shop cloth 3M-77ed to the working edge
Now, you continue until every fret has “SOME” of the crown exposed through the marker ink you applied.