I do not know the name or style, but, if you and I are thinking of the same type of "baffled" steam generator vent stack, Miniatures by Eric used to sell it. I do not know if that firm is still in business or, if it is still in business, if it sells this one, still, but, you can find the products at shows. Minatures by Eric labels it as a GP stack set. The set has the escape stack as well as the vent stack. Those are the only ones that I have seen with that level of detail in N scale. There was another firm (J'n'J Trains?) that sold a set of steam generator stacks for EMDs, but it was not that detailed. J'n'J Trains sold the ALCo angled escape stack/flat vent stack pair, as well. I do not know of any firms that sold the ALCo "stovepipe" stack pairs, the pairs used on ALCo cab units, on Electro-Motive cab units or any of the FMs or Baldwins be they cab units or RS-configured units.
Of course, no one sells an N scale Baldwin road switcher. The Lima passenger road switchers had stovepipe escape stacks, but, if they ever appear in N scale, it would have to be in brass, as they were unique to the New York Central.