First off, excuse my ignorance, I couldn’t think of an easy way to find axial curve even just in rhino because the extrusions have different kind of forms.
Even though I don’t know how to write rhino scripts, I think automating these task would be hard if it is not easy to do in rhino itself.
Some extrusions have holes, some are bent, some are hard to say it is profile (well, plate or something?) It seems that bent parts are made with sweep and some are extruded and trimmed.
Obviously, straight circular extrusion parts would be easy to find, but each type would need different approach to find what you need.
Assuming that these are just part of the whole project, it would be better to provide at least list of extrusions you have included in the whole project to help any people who is capable of providing solution for you.
Maybe a picture of the whole part you are working with if it is cumbersome to do.