I visited Mick 3 years ago and he presented this to me just before we visited the Hippodrome.
This is considered a treasure for me so it is not available but maybe having a picture of this will help in your search for one.
Perhaps Mick's family still has them or the locksmith association outside of London knows how to get them.
He was heavily involved with the association and they should be easy to contact.
If you have troubles, I can look on Google or go through my papers.
He made 100 of these keys in 2009
I hope some of this helps.