Re: Partially filling a void
I was just about to add that it sounds an awful lot like a liner.
Good job Faster...
And like you said, access it from below by opening up some access holes large enough to get a socket wrench or something up in there, than fabricate a removable cover. If it is in an area that is not exposed the cover may or may not be necessary.
Courtney is My Hero
If a man is to be obsessed by something, I suppose a boat is as good as anything, perhaps a bit better than most - E.B. White