Hello!
Although we cannot see the character of the assay office, I think, your item is from Wien, and there was an A.
As I know, at this time in Wien with this monogram (E.S.) the only one who used the "double eagle mark", is Eduard Schiffer. But I've never seen his marks with this stripes.
You could read about him:
viewtopic.php?f=38&t=35107&start=60Best regards!
Krisztián