Here's what I did. (I dearly miss the metal fabrication shop at school)
First I cut up a soup can I pulled out of my recycling. I cut out two sides, leaving the bottom; if I had done neater work I might have gotten an ashtray out of it.
Then I used the bench vise to flatten the curve, beginning with the hemmed top. Then some hammer love to flatten it more.
Then I hemmed (folded over) the edges to make them safe. More folding until I had a tab that was about the right size. I crimped it very tightly on to the existing tab, but that wasn't enough; it still slipped off easily. So later I drilled a small hole and used a small nail as a drift pin.
Repeat for the other side.
As for cutting the rack, the bolt cutters worked fine. I only had to make three cuts.
There it is, a half-rack 22. Now I can run it like a hibachi, or as an indirect with the lid on, or run it with both halves in place like Nothing Ever Happened. In that case I can still lift one side to add fuel or work the fire. The racks sit nice and steady.
I am having no luck with editing the attachments. Looks like I have to start a new post.
Edited to add, after several attempts, I give up on trying to post the attachments. I wrote new posts as replies with the attachments, and when I click Post it kicks me into Begin New Topic and the reply does not show.