Very unlikely, because you can't cut leather to size, like the rubber it's designed for.
You could ask a custom strap maker to design something for you. You'll need to take in to account the watch size, the clasp size and your wrist size to get the right fit, although there is some micro adjustment in the clasp. The strap would have to be designed like the short end (12 o'clock lug side)of a Breitling Leather Deployant Strap - two pieces.