Japanese Bronze Eagle

Hi all. I have two questions about this statue I just bought.

This is a Meiji-period (1868-1912) bronze okimono (decorative Japanese display object) of an eagle. It sits perched on a bronze stand affixed to a marble base.

Two questions:
(1) Is the marble base original? The nuts on the underside and modern washers between the stand and the base make me think this was a later addition. I have seen a similar okimono stand that does not have marble under it.

(2) What is the purpose of the hole in the eagle's back? It is not damage and is part of the cast. Is it for a plant or something else?

 

Have the legs of the stand been painted over? I'm noticing the screw head, now a bit chipped, looks like it was once the same color as the surrounding material.

Could the opening on the back be for an additional element that fit into it? As you say, not for casting process & a very specific shape.

The pink marble does look incongruous, doesn't it? How steady would the piece be without it? If something does go in the back, perhaps it was top heavy & prone to being knocked over.