Hi John,
Polished aluminum on planes is a real eyecatcher and neat detail to set one's craft apart.
I don't have polished aluminum on my plane but I admire those who have because it is a neat a look and I know how much work goes into it.
FYI - we have two 50's vintage aluminum skinned planes at our field that are kept polished all the time. A person does need to invest time to keep that shine up.
Also have a person with a new kitfox build at the field with polished gear legs.
I don't know how much metal polishing work like this you have done before so if I ask a stupid question - just forgive me. Question is this - what kind of polishing compound do you have to use with the wheel? What kind of RPM do you have on the wheel?
I think you are on the right track - it's just a matter of working the surface with one grade of material before going to the next finer grade.
Sincerely,
Dave S
KF7 Trigear
Dave