dadiOH wrote:
DerbyDad03 wrote:

Groove or on top of a batten? How is it attached to the sides? In
either case, how much do the sides extend below the bottom?

Grooves in the sides and front. The groves extend about 1/2" below
the bottom panel. The bottom panel is now kind of bowl shaped,
sagging left
to right as well as front to back.

Simplest fix is 3 screws through the bottom into the back. Put one
in the center first, then one more on each side halfway between
center and side. That should fix the sag in both directions; if not,
slack off the last two, add another one (two more total) between them
and center, then tighten the loosened one.

Addendum: That will remove the belly in both directions as long as you
assure that the bottom is fully inserted into the front groove while you do
the screws.