hello, i have a SB team 753 butted reynolds raleigh, the lugging is thicker than previous models as i was researching and its a bit heavier as well. the frame color is a medium blue, it came with the soft learther version of brooks saddle makes, it has a 1978 dated nuovo record crank set as well. the serial number is sb3776 im trying to find out what era it is 70s? or 80s? does any one know?