666 Made In England - very strange

[Alilpuzzle]

I recently bought a powder compact on eBay and when it arrived it was a bit too heavy to be silvertone.
I've since tested in four places deeply for solid silver and everytime it was positive for sterling.

I've handled items with minute hallmarks so I often know what to search for but this has really stumped me.
Why would it test for silver , say made in England and not have the lion passant or any other markings?

http://i.ebayimg.com/t/666-Made-In-Engl ... ~60_58.JPG

Please let me know.

Thank you.