Hi Eddie, upon inspection there are a few things we need you to sort out.
We start with the forearms and it looks to be some return still on there so removing it or providing a photo that cleraly show there is no return is the first step.
Next are the snaps and although there´s no specific mention of them not beeing painted to get the desired look of metal/crome we feel these need to be replaced or make it look like it´s not painted. I feel the simplest route would be to change them out.
Lastly we have the blaster, apart from what Joseph alredy mentioned, the back part of the hengsler were plastic so it too should not have any metallic weathering. A simple solution would be to give the entire blaster a coat or two with some flat black.
Keep going Eddie - Centurion is around the corner