Now is it me or ......
Tszars were rulers of the old Russia, pre WW1 for the ease of things.
The symbols used would have been Ceryllic?

In that time frame, and after seeing Reval is a place in Estonia my guess would be old Prussian (Germany, Kaizer Wilhelm).

That was my 2 bits of info on this.

Luck on finding more info,
Hoekie