On Saturday, April 9, 2016 at 8:09:44 PM UTC-5, DerbyDad03 wrote:

The biggest problem with the dresser is that the bottoms of the long
drawers sag a bit (actually, a lot) so I may need to add some "beams"
to flatten them out. (suggestions welcome)

In any case, the insides of the drawers are finished and I don't want
to replace the bottoms. Again, suggestions for flattening them would
be most welcome.

Can you easily remove the drawer bottoms and flip them over? If so, then all you'll need to do is (sand smooth? and) apply a finish to the "new" surface.

Sonny