Last bit of work done. I milled the head down .95mm at work, and finished it with 120grit on a machined plate sander (My own creation for our mill) to correct the surface. Mainly because our bits at work suck and don't leave the best surface finish for such a large area. Final measurement .9902mm, or .3898" because ten thousandths matter.
I decided to go a bit more than I intended to make up for the small increase in chamber volume from my efforts in unshrouding the valves.
Taking the head down this far definitely removes a good portion of the "ring" machined into the outer edges of the combustion chamber. I went back and smoothed those out with some 320 grit emery and then lightly touched up/polished up the chamber with 800 and 1500 grit just because I could. If you look hard you can see the three little nicks from my die grinder chuck
that I smoothed out. Even when being careful...be careful!
One thing I am very pleased about is my efforts to unshroud the valves paid off. Taking the ridges back a little from the outer edge of the chamber, and then decking it, left that path completely open on both valves. Now they should have free flow in every direction.
All I need to do now is lap those new valves in, check the seating, and then paint and assemble it, or vice versa. Once I know my valves actually seal I can CC the head and calculate what my actual compression will be.