jea:
Great info, thanks.
As the OP just brought up copper content I recall that the early 5262 and/or 5263 used a high percentage of copper in the brass used.
This said, many things have changed since then (so many design/material changes).
Tried researching old posts on the mentioned receptacles (I was involved in a few of them), but it’s way too much reading for me.
Need to save my good eye for watching TV and maybe driving the car.
DeKay

