Conv. top photo, is there a piece missing here?

[saaber]

Trying to track down source of a top leak. Drains looked pretty clean. In putting it back together, it looks like there is a piece of pan liner missing in the middle here. The thicker foam with attached vinyl is there in the middle but there is no 1/2" thick foam liner on top of the thicker foam for the middle section (notice that the 2 side 1/2" foam liners are there). Is there supposed to be a 1/2" thick foam liner piece in the middle here? Thanks for your help!