Nicely done- and a very good write up.
Sometime fairly soon I want to flatten my old type 6 #8. It's actually quite straight (or maybe pleasantly convex) along the length- you can joint narrower edges well. But the sole is heavily convex across the width- actually flat in the center and falling off to either side, maybe up to 0.010". Haven't measured but it's significant.
This plane was obviously lapped at some point prior to my acquiring it; you can still see some pitting from the original pre-lapped surface in a few areas. I figure this convexity was almost certainly caused by ham-fisted lapping. So I guess there is some credence to the warnings you get on the blue forum when you mention lapping. Although honestly I don't know how you could get this kind of error to this extent. Maybe if you just lap for 8 hours at a time and totally zone out?
Anyways I plan to do 95% of the stock removal with draw filing. I'm considering a fine flexible/vixen file attached to a gently curved wooden form with handles on each end. It's no 12 minute job, but between that and small 80 grit sanding blocks I think I can take care of without too much headache.