The nutzert part is easy but I'd be worried about it pulling out or more likely bending/tweaking. I would think for pegs you'd want a welded-in insert or tab similar to how the factory would mount items.
I like the clamp deal. Something scaled appropriate like this:
I’d go with the clamp if I were you. That way you aren’t messing with the integrity of the frame at all. What’s the OD right there?
There’s probably a few different names.Is there a specific name for that wonderful clamp?