I know it may sound crazy, however, preparing to make a mold and your original part is not perfect. Sanding it to make it as perfect as you can, because the mold will take on any imperfections that are present in the part...keeping  in mind, that this mold will allow you too pull several parts from it......just wanna confirm my thinking...This stuff is ex$$$$$, too x$$$sive to make many mistakes

How/ would you handle the sanding process, just as you would with any surface. Different grids of sand paper, too obtain the surface you desire?

Because too go out and buy all new parts, to make fresh molds would be$$$$$.......