My watch repairer said that the threads on my 5513's twinlock crown were quite worn and it would benefit from a new crown and tube. As they were the original parts from 1969, I decided to go with his suggestion, though ideally I didn't want a triplock.
He came back to me saying he'd located some NOS twinlock crowns and correct tubes (# 7000?). I'm just not sure there would still be any twinlocks around now... Does anyone know if twinlock crowns have ever been remanufactured / faked? And if so are there any reasonably obvious ways of telling this?