I do not know if Edge III existed 13 years ago, but well last owner could have changed it or it is in fact a 3 year guitar. If I am not mistaken,
http://*****************.com/resource...III_bridge.jpg that is Fixed edge 3. The
bridge itself looks like the tremolo version, but pay attention to those screws that attach it to the body. That part looks completely different. Sure you could, but I do not where you could get it and I assume some work should be done. An easier alternative I suggest is to open the back trem cover an put a block of wood between each side of the bridge's block. It would block it completely, some people say that adds sustain, I haven't tried it, and I'm sure you wouldn't have to stretch strings and use the padlocks at the locking nut.
http://www.fretnotguitarrepair.com/i...oloblocked.jpg
Use the search function, there are lots of people who have done this, or you could look at project guitar.com, there is a tutorial on converting a tremolo guitar into a hardtail. Hope this helps