Unknown Rocker Ink Blotter

[hpidaves]

I apologize if I've posted in the wrong area, but I cannot find a maker's mark on this 5-1/4" silverplate rocker ink blotter. I've taken it completely apart but cannot find a mark anywhere. Any help as to where to look, or a guess as to maker or age, or country of origin, would be greatly appreciated. The steel screw coming out of the bottom of the handle I would think would be of importance as to age.

Thanks.

Dave