At this point, you really have nothing to lose if you polish out that rash. I say you end up ahead if you do it, instead of riding around with the unsightly rash........unless you might consider it a sort of badge of "experience"?? I guess it could be all in good fun.

I did remember my racing friends in college that wore their most recent racing road rash on their bodies like they were something that makes them interesting....I guess they did, specially to our female classmates that seem to catch their attention.......those real brave and exciting, live the life to the edge, bike racing men!

I suggest that you dismanntle the RD to as many separate pieces as you can and hit the rashed parts separately with medium grit sand paper first to knock down the deepest scratches and gouges, then use one of those flexible sanding foam sponges at finer grits (400 to 600) then hit it with scotchbight to give the part's finsh a final directional grain, then aluminum polishing compound on a buffing wheel for the mirror finish!
Try to minimize the sanding and polishing at where the pivot and screws are mounted and moving/pivoting parts interface so you do not induce too much looseness at the joints if you take off too much aluminum at those areas when you do your sanding and polishing.
I'm sure you will be happier owning a refinished/polished part than and original but bashed up looking one.

Chombi