HMS Dido lifebuoy


I am a member of the HMS Dido Association and I have been assigned the task of finding a lifebuoy bearing the crest of our old ship.
We think the Bolton sea cadets nicked, sorry, borrowed the original when she was de-commissioned in '83.
You know the type. The one displayed by the brow on what I think is called the crucifix when tied up alongside.
Does any old matelot out there know where these are made, or where we can get our paws on one that is surplus to requirements?