Posted 6 years ago
I know, there's a crack in the glass where somebody put a bit too much effort into tightening the screw. Still an interesting piece. I deleted two photos and will make new ones in the morning.
About the marks - not exactly the same marks as what's on my piece, but close enough for me to date it:
"Marked by the ostrich and two inscriptions "WMF" and "G" (Geislingen an der Steige) in a rhombus, placed in hatched rectangle. Note the special shape of the "F" letter. The rectangle size is 3.7 x 4.2 mm (or 3.7 x 4.4 mm).
The additional marks: "B" means Britannia metal, a zinc-antimony-copper alloy which served as a base metal for silver plating, "I/O" means normal silver coating which is equivalent to 1 gram of silver per 1 dm2 of base metal surface, "OX" means oxidized finish. This mark was in use from around 1900 until about 1918. "
Thank you to my friends for solving this "Mystery"!