Extending curve along a curve

I’m doing a sculpture and basically need two curved sections of metal to overlap so they can be bolted together. I want to extend one curve along the other curve. I have tried smooth, arc, match and cant get the result I need only for a very shyellow moon plates only.3dm (77.8 KB) ort distance.

I have your file open and I can’t make sense of your description based on what I’m seeing.
Can you please describe what you’re after in more detail?
Which curve are you trying to extend and what curve do you want it to follow?

There are two curves on the bottom and one on the top, so three curves altoghether. forget the top one. I want one of the two bottom curves to overlap the other bottom curve, following along the same curvature by about 1 grid block

So the two green curves on the lower extrusion edge? You want them to overlap?

Why not just Match them and use the Merge option, then Copy the single curve in place, then Trim each one back leaving as much overlap you want.?

I don’t know this is the what you need-