Duckingham Palace Multi-Cache

A tricky multi at a fun place.

Duckingham palace has been there since my wife was a child, over 3 decades ago, and our kids love visiting it too (so does the dog, but mainly for a drink or to bark at the ducks).
Currently there is a family of coots nesting near the palace, please give any cootlings respectful space.

The info for the final location is hidden at the listed coordinates, you are looking for a small bit of metal with numbers on.

Coordinates are: N53 45.(larger number) W000 47.(smaller number)

The final itself is an easy find, the info to get there is not!