I have what I think is a 1969 Raleigh Sprite. I'm dating it from the SA hub. What I can't figure out is that the Sturmey Archer Hub says it's a 5 speed hub but the thumb shifter is a 3 speed S/A shifter. The bike seems to be all original so I don't think that the hub was switched. To confuse matters even more I have seen a Sprite on the Old Roads site that has a 5 speed hub, a three speed thumb shifter and a top tub shifter?!? What is the proper configuration for this bike? How does the 3 speed shifter shift the 5 speed hub? Help please.