Part Identification and dimensions!

[actnuts]

I recently purchased my first sailboat!
1978 O'Day 25
Kept wonderfully....Except....Under one of the settie cushions the cover that keeps the seat cusion from falling through the hole is delaminated and useless.
What is the name of the part and does anyone have the dimensions?
Thanks!

 

[Don S/V ILLusion]

This may not be helpful but are you referring to a piece of plywood access panel to the storage area under a settee?

 

[geehaw]

It's just plywood and the fiberglass is indented in the space where it sits. And I believe that are all the same size. Just use one of the others as a template or make a cardboard one to fit the indent. Greg