If I were you I'd get under there with a big screw driver and poke the heck out of those areas to see if they are perforating. The pics are good, but I dont think you can tell how much damage is going on until you gouge into those areas. I ended up paying 500 to have some reinforcing places welded on last year on my 98. The rear shackles were junk.... but it seems fine now.
After, I hosed out the inside of the frame and squirted an Eastwood product internally....its some nasty green stuff that claims to infuse the whole interior of the frame with a rust proof coating. Its too early to tell how well it really works, but it seemed to give great coverage.
Later this fall, I'll take on the out side of the frame with Chassis saver.