id tag

[rustbucket]

high up on the bulk head panel, under the scuttle flange on the near side of the car is an id tag of some sort. its held on with 2 self tapping screws and is painted in the body colour. it must have been fitted before the final top coat because its black underneath. to the far left is a 6 digit number ( 234887 ) stamped through to the back side, to the far right is a 6 digit number ( 455573 ) stamped on the outside surface. any body know-
what it is ?
whats it for ?

its on a 66 2door saloon

[PSL184]

It is the Nuffield body id tag what would today be called the body number. There would originally have been another plate on the front left tie plate carrying the same numbers but they tend to rot off.....