What a curious item, about the only thing that fits is a plated denarius. Leaving the SC in is a complete fail though.. Perhaps it was made in the provinces, and the locals wouldn't really notice the anomaly.
22 mm, I will send this strange piece for cleaning, then I will take another photo..The mystery is the weight and the silver plating..
I eagerly await the photo! Very anxious to: 1. See what it actually is. 2. See how well it cleans up. 3. Once again, compliment you on your uncanny ability to find some really neat stuff. Wait! I don't have to wait to tell you how great it is to see history unveiled and preserved through your efforts and determination. Wish I could go with you, but it would just slow you down. So, I'll sit here "anxiously awaiting" your reveal! And, I fully believe that you know I'm totally serious! Thank you so much, my friend. Stay safe and keep on!!!