My Brother in Athabasca makes a ton of stuff out of leather, including some very nice rifle slings. He has a bunch of videos on youtube of him making many of these items.
He should be able to make exactly what you are looking for. PM me if you want his phone number. Check out his facebook and youtube page for a number of his projects.
https://www.facebook.com/NoarthCreations/
https://www.youtube.com/channel/UCJM...PQG8x64u6eVdJQ