Ceramic bookends - origin, age and maker help

Picked these up in support a recent charity drive. They are not marked beyond what I assume is a mold mark impressed on the bottom. I have been unable to locate any images the same and was hoping someone may be able to identify their origin, age and maker.

BTW the way when you shake them you can hear material inside, I assume this was put in to provide some added weight, but a little voice keeps saying drill…

Any feedback would be greatly appreciated. Thanks

 

So do you think they may have started out as "bookend" banks with removable stoppers?

 

They're very likely Japanese and you are probably correct that they are filled with sand.

 

They could be Japanese. The table had Noritake, German and UK pieces, among others. I have a lot of early Noritake pieces and I can't explain it, but these just a different look and feel, was kind of leaning towards German, but likely influenced by the subject matter clothing, etc. - Thank-you for the feedback.

 

One of my houseguests (friends of foreign student workers) a couple of years ago pried up the bottoms of my antique silver candlesticks because you could hear rattling. I guess they thought there were diamonds hidden inside. Nope. Just plaster fragments from being weighted.

 

I had a pair of filled bookends once, broke the plug and emptied them. Really surprised at just how much sand was inside.

 

I'm leaning towards German based on the five numerals on the bottom. I've never seen a Japanese piece marked that way.
Don