MNCW is for the reporting marks of Metro-North Railroad. I wrote a book a few years ago on Metro-North's history, so this is a nod to the railroad.
It could have just as easily been something Pennsy-related due to my love of the Pennsylvania Railroad...or the New York Central's Putnam Division, as Peter mentioned. I grew up in Westchester County when the Put was still running.
For the Jeep lovers, my favorite vehicle that I ever owned was a white 1983 Jeep CJ-7 Renegade (with blue stripes).
My layout is just an oval on my workbench for now. When I was in Peekskill, NY it was the Peekskill Connecting Railroad. When I build something here, it will be the Yonkers Connecting Railroad...anything to connect my Pennsy steam switchers to the outside world.
Tom