I'd suggest designing a single multifunction blade which could be installed onto a standard Leatherman or Gerber mulittool chassis. The multitool already covers the general functions (screwdrivers, pliers etc) far better than anything you're likely to come up with; try for a design which can help with altering sights, put together the cleaning rods, even clean out the chamber locking lugs if possible. Something like the right hand arm of the SA80 tool below:Kind of, its like a mix between a leatherman and a combi tool to try and get the best of both worlds in one.
Also, separate to the single blade, a screw thread at one end of a handle for cleaning rods / brushes to be mounted on.
The stumbling block will be getting any Army to agree to issuing something specifically for weapon maintenance to the user which can be used to take the weapon further apart than field stripping.
Your idea has merit however; good luck.