I don't know about the purple, but if it's anything like the Flambouyant red they used, your dad surely had a legitamate reason to paint it. Examples below; 2010 took and extra tank and painted to match the other components, yet added the red and white graphics and a decal. 2002, The blue painted in 84 still holding up. I painted two bikes worth of components back in 84, and have yet to need the packed away set. 1976, having owned the bike 2 years, I used paint remover and stripped the original paint to the metal. Painted blue with rattle cans. This repainted bike was an attempt to match the flambouyant red. At 2 years old, "1974", my bike looked close to this example below. Red fades to liver. There is good reason to hang on to your old bike! At one time, (late 70's) I put up a 2 week ad in the newspaper and never got a single call. What was the unwanted bastard stepchild of the failing 71+72 bsa line-up is now much more desireable than it was. And like they say about McDonalds, I'm loving it!