it's my understanding that with Reynolds tubing, each number means parts per...in terms of properties. like 5 parts of a certain material, 5 parts of another material, and 5 parts of yet another.

i recently picked up what is supposed to be a 1981 super course with 555 decal. the frame is black with a gold head tube panel. the headbadge says japan on the back, and it came with 27" Araya wheels, Sunshine hubs and Suntour ARX deraillers. i've had little luck in finding information, except that it's probably either japan or taiwan made. 3A02992 serial number with an N and R underneath. any ideas or knowledge on this? thanks.