Your XM16E1 reweld is pretty nice.
I really think that you should only blast and apply finish to the rear half of the receiver leaving the original anodizing alone.
Using an airbrush tuned to a very small pattern you could fill in a few of the really bad areas of the anodizing.
Give it a chance, then later if you don't like it, you can completely refinish it over again pretty easily with the Norrells.
I blasted, and sprayed the rear half of my braceman reweld with Norrells greyish black flat, and then cooked it at a temperature of almost 350 degrees.
The DoD stamp is still quiet visible.
For what it's worth, I wrapped several layers of aluminum foil over the painted stamp before baking.
I'm happy to say that the Norrells matches the original anodizing pretty good.
Pictures to come later in my 1968 M16A1 build thread.