re: the brace - If you sand the whole top of that brace junction, you can two part epoxy (jb weld or permabond or whatever) a metal T to it (preferably one on top and one on bottom), and it'll be stronger than that plastic brace ever was to begin with.
Or you could get a piece of 5/16 plexiglass about 3-6" wide and weld-on across both the front and back of the tank at the brace, gluing then clamping the new brace to the rim and the tank front-to-back (so the new brace is under slight tension). The only worry with this is it might build up some crud between the old brace and the new plex and be ugly. But it's also at the top of the tank, and nobody ever said you had to use clear.
I think it's an awesome deal, I am always looking for cheap tanks, but in my area I only seem to end up with hexes!