I just noticed

[Snoopy47]

Looks muzzleheavy. Lotsa bling though. Does that belong to BP?

The compensator almost weighs nothing. I have a brass slug/magazine well in the grip/void, and a tungsten guide rod.

^^ What is the purpose of the angled plate located in front of the optic on these mounts? Is it to keep muzzle blast from the comp off of the optics lens?

Yes, I have this same sight on a 1911 right behind the ejection port and it gets quite dirty.

And yes, the barrel, slide, and frame all have the same S/N