I was recently looking for 19mm leather straps for a new Omega I purchased and to say options are limited is putting it mildly. I ended up forking over $180 to Omega for the original strap. My other options were custom Camille Fournet or Jean Rosseau, and neither are cheap (with CF having quality control that can be greatly improved).
However, recently a collector friend turned me to a strap maker based of out Indonesia who's relatively below the radar. His Instagram handle is 'pratamaniwre' and he does custom straps starting at $105 and can dye leather to any color you like. I have a couple straps on order now, but my friend already received his set and they look pretty fantastic.
Thought I'd pass the information along, in case anyone else is in the same predicament that I am in.