Iron works (custom wrought iron) is a still a curiously big business in NYC-- custom iron gates, window gates, decorative wrought iron elements.. results in several iron works in ever borough of NYC! (they don't call themselves blacksmith, but they do the same job, custom fabricating from raw iron. ) like coopers, they hang on.
and NYPD alone has enough horses to have a full time farrier on staff! there are stables uptown, and downtown, and in Queens, and Bronx.. there might be police stables else where (brooklyn/staten island)
there are plenty of public stables too, again, every borough has at least one, some several, riding academies, where you can stable your horse, or rent one to go riding. so i suspect there is a least one, or two private farriers -- not to mention the ones at the race tracks.
SUNY Westbury, has an equestian program,* and all of Long Island's north shore has horses.. (i live in queens on the north shore (of Long Island Sound)
the Long Island part of the North shore has a lot of money, new and old.. (see the movie Sabrina-either version) and lots of horses--and some farriers.
*but the only school(i know of) to train to be a farrier, is in Kentucky.
