I started documenting this build/rebuild on the "Show off your Freshwater!" thread, but then realized it should have it's own thread. So for the sake of documentation, the beginning of this will just be a recap of what I've already posted in the other thread.
This tank started off looking like this. Up and running for probably 15 years with little attention or maintenance. It was originally put in place to hide the poorly made ledge that it sits on.
Untitled by Penny, on Flickr