Nicely done sir!
A couple of notes:
1) I seal my leather liners completely before applying the leather - I use either my period varnish or Deft. This prevent ANY moisture from being introduced into the leather by the wet rawhide. I had some "troubles" with moisture being retained by the leather after the rawhide dried and causing some rust problems.
2) I also glue the damp rawhide to the liner along the center of the liner to hold it in place. Cheap super glue work great for this or you can be more PC and use hot hide glue (the room temp hide glue won't work for this). Hot hide glue can be purchased or just use scraps of rawhide and bring to a slow boil in enough water to just cover it. Once dissolved turn the heat down to low - it can be saved and used again.
3) Like John I glue my liner parts together just as if I were making a regular sheath. When adding a braintan inner liner to the upper part of the sheath I glue it with a fabric glue (there are several brands I Like Tear Mender). To make sure there is no shifting I also use cut tacks aka carpet tacks of various length as needed - these are small square shank tacks found at any hardware store and clinch over very well - a great friend!
4) Like you and John have found I like to round over the edge well instead of leaving the boxy. Besides a safety skiver you can use a #6 edge rounder or a 3/8-1/2" French skiver. If the edge transition isn't real smooth I use my belt sander to smooth things out. Before skiving if you dampen the leather a bit it will help keep things smooth.
5) For belt loops - I keep several widths of 8/10 oz leather pieces and set into the belt loop while drying - it will form around the leather and leave a nice open loop.
Also I wrote this tutorial on making a rawhide lined sheath with a braintan cover sometime back - most of the procedures can be applied to the veg tan liner/rawhide cover style
Anyway again nice job!