True to scale, extra fine modeling, accurate to prototype in every aspect. Very specialized, purist oriented scale type. Code-87 wheels are considered correct for P64n3 modeling, scale exact in detail as to the prototype wheels being modeled, wheel tread diameters of; 26, 28, 33, 36 and 40 for rolling stock and tender applications are available. Even the gauge, "track spread", has to be custom designed for locomotive/rolling stock wheels, of the code-87 variety, to negotiate tight radiuses, custom hand laid turnouts and crossovers.

As in Sn3 the Denver and Rio Grande, Southern Pacific Coast, Yosemite Valley and many others are generally modeled as P64n3 layouts. Quality, period locomotive and rolling stock, finished or as kits, structure kits and other layout compliments are available for P64n3. See the manufacturers links section. Track availability is sparse, be prepared to hand lay track. Period layouts generally depict rugged mountainous terrain. When structures are presented they are S scale.