Last Flight Mystery Cache

The cache is not at the posted coordinates!

My cousin Nathan recently returned from visiting our great-grandparents home in Stonebridge, a small community south of London.
While there, he explored many of the old buildings on the property.
In one of them, he discovered a grand old car, covered with tarps, that probably hadn't seen the road since World War 2
In the car's grillwork, he found the remains of a long dead pigeon. A carrier pigeon, it turns out, on it's fateful last flight.
Still attached to the remains was this note, an undelivered message from a long dead sender in some sort of code.
He sent me this hoping I could maybe figure out what it said.

Perhaps you can help me.