Sessions Regulator pendulum bob cover questions

[ChimeTime]

Nice Sessions time-only Regulator which has never (to my knowledge) been out of service.

I have questions about cleaning the medallion covering the pendulum bob weight.

It seems to be a piece of thin stamped brass sheet (?) with some kind of stain over a major part of the center. The medallion covers (but is separate from) a plain cast iron bob. I'd like to clean the decorative portion, but have questions before proceeding.

• I'd like to know what type of stain it is. Cleaners don't touch it, so it seems to be "in" the metal, more than "on" the metal. It looks exactly like a rust stain, but the clock has never been dormant. I don't think it's shellac.
• I'd like to confirm the part is solid brass... I'd hate to scrub it only to polish through and discover it's brass plated steel (thus the "rust stain") or some other material short-cut.
• On the other hand I don't want to paint it either.
• If it is solid brass then I'm thinking the best way to clean it should be a standard clock cleaning solution. "Gleaming" is not required; "success" would be to simply have the stain gone.

This may seem like a simple issue, but with a time-only octagon there's not really much else for the eye to fix upon, so the pendulum becomes a major aesthetic point. And I'm not seeing replacements being offered from any source, new or used. So clean-up is a one-shot deal.

Thanks in advance for any advice or ideas.

 

[Willie X]

Possibly copper plate. It would have been better to have stopped before you got started. All you can do now is stop before you make it any worse. Willie X

 

[shutterbug]

Here's a link to 5 pages of bobs. You might find one that appeals to you. If you do, be sure to keep the original with the clock. It's a nice old school house clock with history.
For me, if the bob is moving I don't think the smudge will be too noticeable. If you really want to try fixing it, try an inquiry over in the case cleaning forum for suggestions.