Help with dynamic arc component

I am trying to create a dynamic valence that can be resized to variable width/height combinations. I have a plane that has a curve on the bottom, and I need to have both sides line up correctly, the issue I am encountering, however, is that when the dimensions change I need the curve to change shape to line up correctly and preserve the correct top an bottom thicknesses. I believe that I need to be able dynamically control the radius of the curve in the center panel, however I cannot seem to find any way to do this in the component attributes.

The corners of the two center panels should line up with the black line that I circled, if everything is working correctly.

The heights of the ends of both panels correctly adjust to the size of the overall object.

Any help would be greatly appreciated. Thanks!

You probably can’t adjust the radius.

Would it work well enough to let the valance become elliptical, by scaling it vertically?

I’m not sure what you mean by letting the valence become elliptical. Whenever I try to scale it I get the same issue with those center panels not lining up correctly.

Could you upload your skp file?

I meant that if the Valance component - assuming it IS a component - is now a circular arc, you could scale it vertically to position its top where you want it relative to the corners you want it to level with.

But since I don’t fully understand how the model is constructed, I may be quite wrong- hence my request for the skp file.

Valence.skp (371.1 KB)

Here is the file, thanks for helping.