Rover P4 - 376 XUR21/8/2011. Newton Abbot Classics.
The Rover P4 series was a group of saloon automobiles produced from 1949 through to 1964 designed by Gordon Bashford. The P4 designation is factory terminology for the group of cars and was not in day-to-day use by ordinary owners, who would have said simply that they had a "Rover 90" and so on.
376 XUR 1950's or early 60's?
See also picture:

Picture added on 09 October 2011 at 11:13
Added by Roger Mason on 09 October 2011.