33-34 diff cover plate

[Lawrie]

In my old 33 the plate that covers the rear end under the rear seat base is a big square sheet metal plate that someone has self tapper screwed in,
I see that there is a nice round recess under it,is the cover that should be in there a wooden plate like the battery lid or a steel pressing,
Any one have a pic of what should be there.
Thanks Lawrie