Bob...
Taking heed of some of the advice here, you might want to consider something like this;
You probably want veg tanned cowhide about 6-7 or 7-8 ounce. Because this gun is going to be somewhat heavy on the carry, cow will support it without a lot of flapping around that more supple leathers will induce.
Assuming you are carrying opposite your strong side, perhaps put a little cant in the holster part of this rig..
If you are likely to need this in a hurry, cross draws will sit better, come out a little easier, and will hang like a sword without the length.
You might consider two back-to-back pieces, stitched and wet molded to the pistol which is put into the pouch in a plastic bag.
As far as your poke goes, think about the carry on the trail. A couple of pouches might do and, for that matter, a thicker shoulder strap can hold little poke bags. Maybe build them separate and attach, maybe build them on the piece itself, wet molded or with softer leather...your call by your comfort.
For that matter, depending on how you feel when trying this out, you might get away with belt straps.
I think that every man a cobbler stuff I posted spent time with wet molding toward the end of the series.
Um juss sayn
