Done well, this is an excellent solution.

You'll need to purchase suitable steel bosses, either the standard lever bosses which take adaptors, or cable stops with a decent size base flange. Fit the clamp to the frame, locate where the bosses go, and mark the spots, and file the backs to match the curvature as close as possible.

Then remove the clamp, gently clamp it to a mandrel to maintain curvature, or simply adjust it to the right diameter, then braze.

If you don't like the cosmetics of this type of clamp, there are fixed diameter clamps which don't have the worm gear cuts and may look better.

BTW -- stops or lever bosses are notorious for slipping down the tube. To prevent this, sand an area on the underside, and epoxy on a formed piece of stainless as an anti-slide stop.