This is an antique Scottish door or latch key - and dates to the late 18th century or 19th century.
These keys are quite specific to tenement buildings in Edinburgh.
The key would have been held by every householder living in one of the tall tenement buildings leaving off the Royal Mile. This key is known as an Odell Key (or French latch lifters), and it would not have opened your own door to the house - but rather used to lift up a door latch to the main stairway.
The spade-like end or the bit of the key was pierced with many intricate shapes, symbols and initials with acted on similarly shaped fixed wards within the lock in a vertical sliding action.
These keys were invented about 1792 and were still made at the end of the Victorian period.
Sizes usually range from 45mm to 65mm.
This key is about 6 cm in length.
It comes with its original old key ring, as photographed.
As you can see from my photographs - my old steel key is in lovely condition. Nice and clean with no nasty pitting or wear etc - it has been waxed to keep in tip-top condition.
Interesting piece of Scottish history from Auld Reekie.
KEY CODE: D
HAPPY TO POST INTERNATIONALLY, PLEASE ASK FOR A POSTAGE QUOTE OUTSIDE OF THE UK.