Originally Posted by Really Not All That Bright
I'm guessing that "not having a filter" thing may be the source of your problems.
... I'm sure it hasn't been helping. But the evaporator was just throwing out so much water even back in 2006 (when the last of the fibrous makeshift "filters" was still in place) that it rotted out a lot of the wood in the A/C closet. That on top of ruining the furnace.
At this point, it will just be better to rip it all out and get a new evaporator and furnace. Thankfully, A/C closet repair, sheet rock work, etc. is included in the installation.