Wow Brucey,
the tank is looking awesome!
I've read through your thread here a couple times, but for unknown reasons I've never posted...
Well, I'm changing that now...
I'll give you a quickie primer on how to tell Acro's from Monti's... on Acropora, the polyps are on the tips of the corallites, whereas on Montiporas, the polyps emanate from 'between' the corallites. If you look back over your pix (or at your tank) you can see what I'm talking about.
That should at least help you narrow down the Genus of the corals really quickly, and then you can try to narrow it down to species by looking at pictures.
As far as the 'rusty' montipora goes, it looks almost like an M. foliosa to me, though it sure does have some interesting growth patterns.
That brain you rescued is looking great as well. Awesome setup... I almost blew my coffee out my nose when I saw your 'water butt'... that word has a bit different meaning here in the states (same as 'bum' in your part of the world).
Can't wait for the next update.
Once again, awesome tank mate.