For the facia bolts I just put them in the dremmel (they fit perfectly) and "pushed" them into some fine emery paper. This removed all of the black coating and gave a nice shiny finish. I should probably laquer them as well as they are probably mild steel and prone to rusting over time. However, to take them out and do the same again would be 10 mins work.

I use this epoxy putty called Hard and Fast for many things and this should be good for your handle filling. It has a grey and black portion with a platicine type of texture which when mixed, set in about 15 minutes and can be filed to shape. If you are going for the complete aluminium look, you will probably have to coat the whole handle again to cover this up.