I always liked the whole gun blasted. The reason I usually did so, was because the "flats" are so easily marred and scratched when polished. Its a lot easier to touch up as the gun gets beat up too.
This is my old Colt Commander that had polished flats and was completely blasted. I used the same beads we used to park with. Not sure of the size, just that they were "glass". I just taped up the front sight and used an X Acto knife to trim and it worked out well. This is the only 1911 I have that doesnt have a dovetailed front sight, else I'd have removed it.
“The enemy is anybody who's going to get you killed, no matter which side he is on.” ― Joseph Heller, Catch-22
Beware of associating with "Cheap" Squirrels. They tend to be very narrow minded, hypocritical, and will gag you if you question or disagree.