BTW, if you decide to that you want to do more than a couple of holsters, you will probably want to pick up a coupld of tools: an edger (to trim the edges prior to sanding) and a stitch groover (to cut a trough for the stitching to lay in, which is perfectly parallel to the edge of the holster).
Right now, I do not have time to post links to these. For a stitch groover, I highly recommend the one that can be used free-hand or with a guide... or you can buy two different tools for that if you don't want to fiddle with it. I use a #2 edger but many people use a #3.
Nick