Thanks for the suggestions. Looks like we'll be doing refurb part 2 this summer.5 years of regular use will likely do in any spray paint job, especially if exposed to weather. Maybe doing a little more on the prep side would help. All the old flaking stuff obviously has to be removed and using something like xylene to clear off all the grease will help the next paint get a good grip. Rustoleum is about as good as you can get non-commercially. I happen to like Krylon's Max High Heat because I think it goes on easier and like the semi-gloss look, but I wouldn't expect it to last any longer.
That top cross member is a part that is under a lot of stress with ample opportunity for rusting. My suggestion is to use Bruce's video as a guide for cutting it out and replacing. I recommend you source a length of stainless steel tubing to make the replacement piece.