Tailoring Leather? (NYC area in particular)

[Yakboy Equals Nurturer]

I recently purchased a leather jacket from Lost Worlds Inc. The construction is great and the 4oz horsehide is way heavier than I could have imagined. (It's going to take years to break this thing in.) The thing is, I'm not 100% happy with the fit. It's fine across the shoulders and chest and the sleeves are plenty long enough, but the cut of the jacket is just kind of boxy. I could probably live with it, but want to see what kind of adjustments are possible / how much a decent tailor who works with leather is likely to charge for making the jacket a little more tapered / fitted and the armholes tightened / raised slightly. Anyone have any experiences in getting heavy leather items - jackets in particular - tailored?

[Thorns]

Although I've never done it, from everything I've heard its a bitch. I'm not even sure my needles would go through leather... and they're ridiculous denim gauge.

[Yakboy Equals Nurturer]

Yeah, I figured it'd be a pain in the ass to do (particularly with leather as heavy as on the jacket in question)...but I also figured that there'd have to be at least a couple of tailors in NYC that do it. I'm pretty sure Ramon Diaz works with leather but I'm not sure if he does proper alterations or just does re-lining and cleaning. I need to find someone who can, at least, open the side seams and taper the jacket a little.