From my very little experience experiementing with cold cast, those shinier (sp?) areas are the result of excess aluminum settling in those areas during the curing process...be'd nice if the entire helmet looked like that...but gotta work with what you have. However, from what FP stated, your helmet has the potential to look like the one in his pics. So, the polish won't take out those striations. I'd just do some light rubbing in circular motions with #0000 steel wool in those areas that'll be exposed. Maybe throw in some running water to wash away the accumulating residue as you go, and save the polish for the very end to help create a fingerprint repealant surface.