I'm new into N scale I'm a little confused that USA N scale is 1/160, Japan 1/150'and Britain 1/148. Do all the N scale mix well or if I start with one should I stay completely in that exact scale for a good continuity?? Also how do I make sure the exact N scale the product is, is it always stated on the product description?? Anyway I would appreciate any advice as I am new to this and don't want to make any mistakes right off the start.