One of my first 'real jobs' in high school was 'chief' bike mechanic at Sears during the 70s bike boom. No training required
In between assembling/repairing bikes and dealing with customers who expected their $59 POS Free Spirit bikes to perform like $700 Paramounts, I'd take 3-speed hubs apart and reassemble them for fun in my little shop in the back of the auto center
FYI: Sears did sell a top-of-the-range bike with a 531 frame. I think it was made by Puch in Austria. I got my hands on one eventually via a shipping screw-up but it wasn't anything special. It had gold paint. Edit: pretty sure it had Campy Record derailleurs with an assortment of other components.
