PBP, NICE work, looks good.
One trick I have used in the past is to install a sacrificial sight. With the throwaway in place you can blast away and still maintain the smooth mating surface on the top of the slide yet get full coverage.
When doing revolvers, I use the same principal but replace the screws and/or pins with space fillers. This stops the edges of the holes from dishing or abrading.
All things being equal, fat people use more soap. (I know I am one.
) High speed, low drag does not even come close to describing ME.