Is it me or does it look like the handle straps area where it meets the lid are yellow? Looks like someone already did something to fix a problem there. It might get hairy trying to mess with that area too much. My handle on my SSP popped off. I bought it used so I have no clue what the previous owner or owners did to cause it to loosen up. I just drilled through the handle and lid then attached the handle with SS screws. No washer on the outside so it wouldn't be so obvious then a really big washer on the underside of the lid and then wings nuts so that I could tight them up after a few cooks really easily. I figured heat would cause them to loosen and it did. I have to tighten then every once in awhile and since I don't need tools it makes it nice and easy. I also figured finger tightening would prevent me from damaging anything.
http://weberkettleclub.com/forums/weber-kettles-accessories/my-1st-rescue-1991-ss-performer-red/msg212818/#msg212818
I have been the only owner of this performer; it is a 2002. The yellow is what is left of the rust under the handle. It looks worse in the picture than it does to the naked eye.
The weld between the lid and handle is rusting out and some of that rust has dislodged, leaving a little gap between the lid and part of the handle. The rest of the handle is still welded. Where the rust dislodged, there are small holes, about the with of a pushpin. My original plan was to do exactly as you suggested. Drill through the handle, put washer and nut under the lid, to cover the hole and prevent the handle from coming completely undone. Gummi Bear suggested I leave it alone, other than the rust.
I am going to plug the three small holes in the bowl, all about 1/16 inch in size, with sheet metal screws...no nuts or washers. There were a variety of opinions on what to do about them, but no consensus.
Other than the holes, the lid and bowl are pretty much finished. I am almost done with the ash catcher assembly too. I'm debating whether to make the interior of the catcher like new, or leave it stained. The rest of the catcher is almost spotless, as is the ring that holds it. I took off all the rust to the ash catcher handle and will paint it black to inhibit future rust.
I hope to disassemble the frame this weekend and rebuild it. Will replace star nuts, and figure out what is going on at the top joints. After that, more rust removal and then some touch up painting. I am sure I will have more questions.