Yeah I definitely will swap out for a new receptacle. I think you’re probably right the brass housing is older.... so the ne is for nema?
No. The "NE" will be the manufacturer's trademark. (Which unfortunately, I don't recognize.)
But, as an electrical engineer, I definitely second the notion of replacing the receptacle with a new one before returning it to service.
And I would apply a liberal quantity of quality electrical tape too, just to be sure.
You will be, in essence, the manufacturer when you rebuild this thing. That means everything is on you.
You do not want to burn your house down, or get electrocuted.
You do not want someone else to burn their house down after you die and this thing ends up in an estate sale (or whatever).
Whatever you plan to do... do it right.
And remember, even when brand new, this thing could have had safety issues. Be careful.
Get professional help if needed, but hopefully does not come to that.