I think all those dark patches are mildew or something. I don't really know what I am dealing with...but google tells me that's what the problem is.
Therefore I bleached it - twice (once with bucket and sponge, once with a spritzer and sponge)! and its was/is still smelly...thats when I decided to sand the insides (with the grain of course). Ick....sanding is HARD DUSTY WORK because I can't get the power sander in there...not that I mind hard work, but I need to dedicate a block of time to get good and dirty...In the meantime, I spritzed it with bleach solution again this morning...I will try sanding the heck out of it this weekend. I figure this has to work - eventually. Worth it? I dunno....check back....
(Its really too bad I postponed dealing with it, cause the HOT summer sun sure would have helped out...not that I can move the beast on my own)