I just purchased my almost grail watch - the Zeitwerk is in the works eventually - a JLC Geophysic 1958 in stainless. The watch was designed to take a beating but comes on a black alligator which JLC usually sources from Camille Fournet. It is a fairly small watch at 38.5 and 19 mm lug width and the strap I guess to be 2mm thick. I would love to put this on more casual shoes especially something waterproof/water-resistant as it is rated at 10 atm. I am not a big fan of nylon NATOS so would love something in "waterproof" leather. However most of the waterproof leather seems to be 5 mm thick and 20 mm wide so I can't see this working out. Can anyone recommend thin waterproof leather strap or leather NATO? What about Chromexcel, I have never seen it but it sounds like an option? Any input greatly appreciated.