Difficulty creating solid from mesh body

Hi,

I'm trying to take a scan and convert it into a solid body to modify and then slice for a CNC router. I have tried for many hours to take the mesh and create surfaces from it using the wizards in SolidWorks. However, I end up not being able to use the surfaces to make a solid because there are holes I can't seem to repair. I have attached the edited scan, and I'll try to attach my current part that I'm struggling with in a comment below. Does anyone know what I need to do to actually convert this into a solid body? It's a pretty complex organic part. I'm not sure if there are any good solutions. Thanks in advance.

SolidworksSurfacing