You have OR straps in either 24mm lug width, 22mm or 20mm. The 24/22 mm tapers down to 20 mm at the end (so if you're getting a 24 mm kit then your deployant will be 20 mm) while the 20 mm tapers down to 18 mm. With the clasp you should be getting you can easily have a 22 mm strap on it instead.
The OR deployant can't really be put on a Breitling leather strap, but if you make a custom order you can get something like this:
Unless you have your own little workshop at home and a big bag of patience you can't fit it to a bracelet.
If it's in good condition, $195 should be a fair price.
ABP is really great to work with. I even discussed with them a while to custom make a watch box but in the end had to desert that idea, it would just have been too expensive.