Dan,
No layout, but worth the visit, I believe it is the last train store in Manhattan. the Red Caboose at 23 West 45th Street.
There is an affordable British pub right next store (to the Red Caboose) that makes the most amazing (and large) Fish & Chips, The Cock and Bull.
If you have time, take a cab to the the West Side, visit the High Line:
Tom