1" nylon strap and a parachute buckle from my local fabric store. Glued with E-6000 and hand-stitched with a machine needle and heavy-duty polyester thread.
I need to make a keeper for the other end of the buckle, because I put the fold-over on the inside, and the burnt end of the nylon strap is rubbing my wrist. I can't flip the buckle over because that end is sewn on. The buckle is a little bulky, too. Definitely not meant to lay against a curved surface, like a wrist.
The lugs on the 47mm MM case are 26mm, and an inch is 25.4mm. The .6mm difference leaves a *little* bit of screw bar showing, but it's not horrible. I think I'll try to find some heavy canvas to make a more vintage-looking version of this to match the steampunk theme.