BBR501 Ex Sunderland F7 PE 1950.Although new to Sunderland this machine was photographed in 1986 at the North East Aircraft Museum, which is near the Nissan Factory close to the A19 Road..
I remember seeing this vehicle on several occasions at the museum until around 1989 when it disappeared. I believe it got used for spares for the preserved Tynemouth example.
Another photo of this Dennis:

Picture added on 02 October 2011 at 17:57
I was not aware that Tynemouth FB has a F7
Added by Barrie Green on 02 October 2011.