Salt is added to the wash water to reduce the 'rag' (frothy area where oil and water is mixed) and make separation easier. It's a commonly used method in the chemical industry. If the oil is dried properly with something like silica gel there will be no residual salt in the oil.
A farmer violin maker wins $30 million in a lottery
A reporter asks him if he's going to retire and he says "No, I'm just going to keep farming making violins until it's all gone."
Perhaps with the tiny button it was baroque made and then a new neck put on it instead of a graft? Disclaimer: I always get stuff wrong when guessing about old violins.
A properly set up 1500$ chinese violin is miles ahead of what you could get 30 years ago in the same category. My son was in orchestra and plenty of violins end up dropped, stepped or sat on.