The dish is 13 1/2" in diameter and 1 5/8" tall.
On the rim of the dish are six stamped letters (each about 3/8" tall). They appear to be:
I V E
S C L
On the bottom of the dish are two marks (each about 3/4" tall).
One appears to be a flower and "I. A. V. G" .
The other appears to be an angel with a sword and "I. A. V. GIESSEN".
Any help estimating the age of the dish and what the marks are would be greatly appreciated.
[I realize these aren't silverplate marks, but it was recommended to use this forum category to ask for help]