Identifying a Tray?

Hello, I need some help identifying what this tray might be worth. I understand I can go to the pawn shop but it's all out of my way and hard to get there. I've been thinking about this recently and I just found it. I thought I'd lost it.

Based on my poor knowledge of testing metal and what I know about antiques, I understand this version could either be silver plated or completely silver. If any of you well trained antiques folks out there have an answer for me or can make out that stamp and let me know a little more information. I'd like to sell it. Thank you.