find the nearest quality leathershop/saddle maker and take it to them. they should be able to make you a one off rig that fits it how you want and it will be built to last. I would enjoy taking it on if I still had a heavy sewing machine darn it. Put some thought into how you would like it to cover the pistol and scope and operate etc before you go. Also if you would like any tooling done on it. you may want to consider a chest or shoulder rig. good luck!