Does the Chamberlain/Hitler 1938 declaration still exist?

The Anglo-German declaration that Chamberlain waved as he arrived back in the UK in 1938 saying peace in our time.
Does that piece of paper still exist?
Is it in a museum somewhere, or in a government vault?
Or did Chamberlain angrily rip it up when Germany invaded Poland?
If it does exist surely it would be one of the most historical significant pieces of paper in our country and I would love to see it