I bought the worst bike on the planet.
That aside, I had to take off the oil tank (plunger A10) to get the mag off, and, as I'm adding a 2cv type oil filter, decided to replace all the rubber oil lines and clean out the oil tank. Three rinses with parafin and the inside was full of small chips of metal. I should have checked them with a magnet, but sometimes I have no brain. Maybe half a thimble full of metal bits. Hot soapy water got the tank properly clean, And I guess that could just be 50 odd years of crud, washed free for the first time, but should I be panicking more than I already am? cheers.