DionCini,
First let me also say "Welcome to our board." I don't think any of us here want to be negative. It is just that these Summit grills have provided a lot of difficulties to many members here who have owned or tried to restore them. Also, as Rich G said very well, Weber unfortunately made some poor design decisions in designing this grill. This is really a shame, because this special edition of the 2nd generation model you have has Weber's BEST EFFORT in regard to the frame and cabinetry. Those being all 304 stainless will last a very long time.
Because you have the two-year-only Platinum Summit with the stainless frame and cabinetry, I do think yours is worth the extra effort it will take to bring it back. From your comments you either can do sheet metal type work yourself or have access to having it done on the cheap. For most other members that is not an option, so the rebuild cost for a project like this can quickly get way out of hand. But for your situation, if you can fabricate the needed parts and use stainless steel wherever possible, you have the potential to have an awesome grill when you are done.
I certainly wish you every success possible in bringing this grill back. It's great that you will be able to fabricate, since as others have said, parts are really getting tough for this grill. The firebox issue and lack of parts also afflicts the even older 1st generation Summit that I am trying to restore. The early Genesis grills, by comparison, are a lot easier to find parts for because (1) so many more were made and old examples are still around and (2) because they were popular, more companies have jumped in to offer non-OEM replacement parts. There is little of that for these Summits, which means you are often on your own to fabricate or otherwise improvise replacement parts.
Please do keep us posted with pictures of your progress. I, for one, would love to see that Summit back in 100% condition with some nice T-bone steaks sizzling on it!