What tlw is saying is so true, I have a friend who's set of 57 and 58's where purchased second hand by him in the mid 70's. We A/B'd them with my newer ones and they sound identical
The wind screens were just filthy so we washed them.
These mike where tossed in a suitcase full of cables for most of there life,,, never looked after. That's why we like them. As I said there are 1,000 of great mikes out there, but nothing like these. They are not great, just legendary.
And a big thing for me is the gain before feedback rejection that few mikes can claim.
Tlw,, there is a difference in the pre amps inside them with a low cut on the 57?? I believe other than that they share the same barrel and diaphragm.I think you can exchange the top parts. The main idea is the 58 has the pop screen. But add a windsock to a 57 and ther eya go/