I just wanted to post this up in case anybody else in the US is looking for a leather horizontal shoulder holster that fits the Taurus PT92 w/rail. I just spent the last week searching out, emailing, and calling leather holster makers looking for one, and I wouldn't wish this frustration on anybody. (That's not exactly true. Governor Patterson, I am looking at you...)
After trying Bianchi, Galco, Mitch Rosen, and a couple dozen other holster makers, I finally found one that makes the type of shoulder holster I was looking for: High Noon Holsters. Their model "Under Taker" and "Under Armor" both have holsters that can fit the PT92 and PT99 with rails. Of course, they aren't listed as such. You'll have to pick Beretta 92FS Vertec to get the right fit. (I asked them just to make sure.)
If you aren't as picky as I am, Bianchi makes a soft nylon horizontal shoulder holster called the Tuxedo that fits the PT92 w/rail. I just don't like generic nylon holsters.