Here's another little tidbit:  Krag's are a different breed.  A barrel with what in Garand or 1903 terms would be considered a bad muzzle gage, should still shoot relatively well.  Jacketed bullets seem to ride the bore well, and you're not pushing bullets to the velocities that you can expect in a 30-06.  Shooting at 1900-2000 fps is plenty fast enough in a Krag, and can be deadly accurate too!  Slug the barrel and see where she stands.  You can always shoot cast... and if your bore sizes .310 or up, you can also get jacketed bullets sized to that.

As for that handguard, I would carefully epoxy it to prevent further cracking, and leave it alone.  As Cat Man stated, I would rather keep my Krag original.

Remember... all is usually never lost with a Krag!