Hi there,

Yes it's feasible.

If you plan to do many parts like this, consider buying yourself a 3d scanner, it will be paid fast. The new Einscan1 from Shining3d is below 1000 USD. Search this forum for more details.

To modify/repair an STL file, Meshmixer is doing the basic stuff and is free. But you'll want to do more and not be constrained to STL files, then 3dcoat becomes interesting.