I have tried to do something similar to Greg. I put my blade in two pieces of Velcro, and then used put bicycle inner tube ranger bands on the belt to hold it in place. Thus it gave me a saw blade, a cover and some spare inner tube for tasks including a method of attaching it to wood. I kept a couple of nails or bolts under the bands or in a pocket or pouch. A full size saw blade is also a lot better that the old commando wire saw in a practical use for processing a large amount of wood.
I did it as part of a test to see if I could carry a total survival kit in my clothes (before everyone shouts out) I did it as part of a survival course, being as light as possible but as complete as possible as well. We were allowed items that could only be in our clothes and no pouches allowed. The method of water was the hardest for most people. We still were working with 2 oz survival tins at that point, my methods have changed since going on more tours and the introduction of other SERE related stuff. I have the Wazoo cache belt and some other belt which I have other SERE stuff in them.
I may recreate it and post a few pictures of what I would now put together for the kit. some things would definitely change and i think would be a lot lighter now as well.