Ahh, yes!
Sorry I had missed the images. The best way to share images is NOT to attach but embed them. The easiest way is to drag them from a file folder right into the post. I work on macOS and Windows and this works in both os.
In windows, if you make a screenshot the images end up on the clipboard. You can then paste (CTRL-V) them into a post at the current cursor position.
What you want to do is at least theoretically possible. However it will require at least one other software than Fusion 360 perhaps even two.
Can you zip and share the scanned .stl or .obj file ?
My workflow in general would be to trim away from that mesh what we don't need in Meshmixer and export it as a .obj. That now smaller mesh we will open in InstantMeshes and re-mesh it into a quad-mesh with much reduced polygon count.
Then we'll export that quadmesh into another .obj import it into Fusion 360 and convert it into a T-Spline and then (NURBS) surface body. that body we can then use e to trim (split body) away the parts we don't need.