I know it's a creamer. All others are questions. Help!

Wife went out picking up little things and this is one of the things she brought home. Normally I’d go straight to the bottom looking for marks, but really can’t find anything on this one. At least nothing I’d recognize as a marking. So the questions are:

  1. Is this silver or silver plated?

  2. Is the black Patina? I did read the section about cleaning silver and I have only cleaned it with warm water & dish soap so far. It changed the color mostly from black to blue with brown tarnishes here and there. The fine detail work on the handle & base still has lots of black in it.

  3. Do I keep cleaning it?

  4. Any idea on age?

  5. Don’t know the specific weight, but it is the diameter of a normal ceramic coffee mug, 3/4’s the height and almost twice as heavy.

  6. Are the markings in the upper right corner of the bottom just marks from age or are they something more?

Really, any answers you can give on this item would be greatly appreciated.

We usually deal with furniture when it comes to antiques and that is very easy to distinguish in comparison to what I’m seeing when it comes to silver just by trying to research this piece and a piece of lead pewter she brought home. It was easier to ID that than this one.

FYI: These pics are before the soap and water bath it received so the black areas are mostly blue now.
creamer 003.JPG
creamer 002.JPG
creamer 001.JPG

The general rule is that if it isn’t marked as silver in any way then it isn’t silver. Of course there are exceptions to every rule but my feeling about this is that it is most likely electroplated. Without markings the only hope of finding out anything more is if it looks familiar to someone. I think that the mark in your second picture are accidental rather than meaningful.