wheel well flanges pretty bad

I took a good look at my curbside wheel well today- and it's in good shape except for the flanges that are nailed to the underside of the floor:

IMG_1932 by kathy, on Flickr

Is there any way to fix / strengthen that without having to replace the whole thing?  I am not taking cabinets out-so getting to the wheel well looks impossible without taking out the tall cabinet.

Any ideas would be so appreciated.  I do have a friend that welds...if that helps

THanks Kathy