Very nice g-man! I'm sure you can see all the imperfections in the finish, but it looks great in the photos.
Even after over 12 years of doing this, I have yet to get a finish that's flawless!

Your wiring looks nice and tidy, and your shielding too. I've seen some real dog's breakfasts, and yours ain't that.

The only thing that's a bit odd is when playing with gain the open G string seems to have an odd harmonic if my hand happens to touch it about 2cm away from the bridge. I can make it stop if damp the strings behind the nut so I'm planning to add some string trees. The nut is a preslotted Graphtec - I tried filing the G slot a little deeper (there was a little room for this) but that didn't seem to help. Does any one have any thoughts on this? I'd rather avoid the string trees if I can.
I'd check the angle of the slot, as well as the width and shape. It may not have needed to go deeper (since you said there was little room to move) but may have just needed a better break angle, make sure the width is not too narrow so the string is not getting "pinched" on the sides, and bottom is a nice uniform "U" shape allowing the string to make full contact with it.

It wouldn't hurt to check the G saddle slot and break angle as well. Your description sounds like it nut related, but sometimes it's deceiving. Unwound G strings can do weird stuff.

The only other addition is a spring to go in the trem arm hole. It's either too tight or there's way too much play and slop.
A little trick with those springs, is to put a small ball of Blu Tak at the bottom of the hole. It will hold the spring in there when the arm is removed so you don't have to leave the arm in. This will reduce the risk of loosing the spring when you do remove it.
A lot of cases won't properly fit a guitar with the arm fitted (and that's a pet peeve of mine, seeing a vibrato arm on a guitar and then the lid jammed down to close).

Oh, and when do we get a demo? (I liked your first one)