Vintage 1800s 1900s Silver and Pearl Key Victorian Brooch

Stunning vintage antique 1800s brooch, possibly early 1900s. In the shape of an ornate key with tiny pearls and rhinestones. Has a push-pull trombone safety catch and round ball hinge. Marked on the back with an M and "Silver" so probably English made. I was unable to identify the specific M mark but it may be a town date mark. The pearls may be real or faux, I will not vouch for either.
Measures .75" wide by just shy of 2.5" long.

Excellent vintage condition. Near mint really/

Please note: These are vintage, preworn and/or preloved items. I do my utmost best to list any issues, but signs of wear should be expected, and there are occasionally small things I won't deem worthy of note. Please feel free to send me a missive with any questions. I'm truly happy to help in any way possible and I'm always up for a chat. Any accessories shown, including crinolines, are for display only, not included unless otherwise stated.