The only thing that hits my mind is, cut the curve in 2 in the center of the curve, and the straight piece opposite. Then weld a piece in the gap of each, however long you want. I've seen other types of tool extended similarly, except the needed flat sections. Might have to overlap each end of the gap, and the insert piece. Silver solder might do the job. If you would be doing the joining, unless you are skilled in doing things like that, I'd get some scrap pieces and make several practice joints. Actually I'm thinking riveting could work, but might get tricky. I'm thinking I might consult with a pro welder before I started on this. He/she would likely know IF it could be done, and if so, the best way to do it.
That's all I've got just now.
"It ain't what you're told, it's what you know." - Granny Weatherwax
Some days, the supply of available curse words is insufficient to meet my demands.
Call me a craftsman, artisan, or artistic, and I will accept that. Call me an artist and you will likely get a quite rude comment in return. I am not a @#$%ing artist.