MGB Tonneau

["Mike Razor" <mrazor@mis.net>]

Time for another dumb question or so!
What are the two tabs in the middle of the tonneau, with lift-a-dot
fasteners for?
Second, the two zippers behind each seat?
Third, what would a new tonneau be worth?  Two came with the car, I
just repaired and refitted the old one, which is like a new one and I
don't see any reason to have two.
Finally, I was told that the two gray tubes are to support the
tonneau, but I don't have the slide-in  mounts for them.
THANKS!
Mike R