Acoustic Guitar Construction

ok, was worrying I was making it worse but it's pretty flat now. With the neck bolted flat in line with the soundboard there's a 3 index card gap by the time the MDF reaches the soundhole. I'll sand that as per the neckset instructions tomorrow.

Mike -- my hope was that you would have realized that this

"I think they probably have a belt sander and can sand it flat at 90 degrees to the SB."

Serves to totally wipe out the work you've already done to make a sound-board to neck block angle that "is not 90 degrees"

Perhaps a review of the concepts found here are in order?
http://www.kennethmichaelguitars.com/neckangle.html

I thought by accidentally missing the step to angle the rim and block at just less than ninety degrees I was now working with the ninety degree angle and sanding the sound board to get The fingerboard to sit flush with the soundboard? I'm pretty sure I'm now on track to do the index card trial to find How much angle to sand into the sound soundboard so it will continue on the same plane as the surface of the neck. Does this sound about right? The heel of the neck is now sitting nice and flush on the outer edges against the rim.

Yeah -- I forgot about the missed step (many KMG kits in process) -- carry on.

ok, MDF fretboard substitute is sitting nicely flush with the SB so i think I'm winning there. I need to blend the slimming of the SB around the upper bout, is now the time to feather the edges all round? How far in and how much would you be looking to take off. I was imagining roughly 5cm in from the edge and maybe a mm thinner at the outside edge? Shall i do al this before routing the top for the binding?

Sand until it blends and looks good -- don't ruin the flat you created for under the finger-board extension area. This is an appearance issue. Yes the instructions state specifically that you need to do this before routing the sound-board channels

I was reminded again Ken on my current guitar build that it is IMPORTANT to be sure the neck join area is sanded flat and level BEFORE routing the binding channels. I thought I had done this, installed the bindings, and now that I'm fitting the neck, I found that I needed to sand this area flat.....arg! Then binding at the top, next to the mortise is now thinner then the rest, however the fretboard will cover it thankfully.
Seems I forgot to check it, so make sure you do so before cutting those binding channels.
I have in the past cut the mortise and fit the neck before starting the binding process, and I am going to go back to building in that sequence for this very reason.

Kevin