Convert Mesh to Precise Solid

I have a faceted mesh that I can supply as a STEP file. It represents a rubber part I captured in Fusion 360 by scanning, sketching cross-sections and lofting, then switching to mesh so I could apply smoothing (and scale to 0.95)... (Budget: £20 - £250 GBP, Jobs: 3D CAD, 3D Design, 3D Modelling, 3D Printing, 3D Rendering, 3D Visualization, AutoCAD, CAD/CAM, Fusion 360, Solidworks)