How is nylon on finishes (like uncle mikes holsters)?
As far as I know, there is not a big problem with it.
One thought, if I might: While the uncle mike's IWB pouch is a flimsy affair, one thing that I do like about it is its' clip for the belt.
Take some suede, and make a pouch with it, sewing it up and then take the clip from the Uncle Mike's and sew it on the suede pouch, and you have a suede holster that is much firmer than the UM nylon one.
One thing I would do is leave the bottom open.
Just doing some thinking out loud.