Wondering if anybody knows if steel miniature tube shields where bare steel or plated with tin or something else from the factory?

Almost certainly steel shields were plated. Rust is inimical to shield operation, since when it forms it can create a nonconductive layer between the shield and the chassis.

I've got a handful of them in a box. All are definitely plated. Some appear chromed, and others are clearly cadmium plated.

A lot of them were tin plated.

Ok thanks to all for the info. I picked up another Hali SX-100, and the shields on this one are kind of nasty. I wire wheeled one off, and though shiny, it's way too dark in color. I'll have to decide on painting them or investigate getting them plated.

Hi Kevin,
As Don says, tin plating seemed to be the most common, and of course this often tends to tarnish. Your wire wheel probably removed the tin plating, leaving only bare steel. You might try another one using just Brasso on a soft rag.

A few times in the past, with shields which were extremely bad, I have painted them with metallic silver high-temp engine enamel. This looks good, but of course is not authentic.

Thankyou Poston for the info. Believe it or not, I did break out my Brasso to try before I wired it and in my case, it just made the shield darker in color for some reason, like a charcoal brickette.

I may have found the answer, the article is about R390 IERC shields, but he mentions regular miniature tube shields are Nickle plated. http://amwindow.org/tech/htm/irec.htm