The one you are referring to is the Horus ASLI. It is made to be mounted and comes with the mount of your choice, but since it is rather square in shape it could be used as you see in the picture. I have one, it's a pretty nifty little piece.
Horus Vision
I've had 300 7wsm brass on order from brownells since january and no word yet. I lucked out and found one bag of 50 locally, but I've kept my eyes out for it everywhere even once fired and this stuff is hard to come by right now for sure.
Great write up, I saw some of your earlier load testing over on the hide. Looks like from the manufacturers specs on that bullet they are claiming .7828 BC (static). Doesn't look like they were very close to that mark. I've been waiting on the new Bergers to decide if I'm going to rebarrel...