There is one in the RAF museum I think I remember seeing one there in 1975.
When I was in Mohawk College in the early 70's I got talking to an elderly security guard one day & it turned out he was a rear gunner on the Defiant. I was amazed that he had survived.
Anyway he swore blind that the Defiant was a Hurricane with a rear turret added (it isnt). It taught me a lesson, that someone who was a lot closer to the real thing does not always know the truth of a thing. Brave chap anyway.
Peter (in Ontario)