No conversion was necessary. I drilled to place magnets on the flat end of the Paulson piece and on the underside of the forearm and attached them. The Fusion Blasters I sanded down on the attached parts. Paulsons parts are incredible, very little cleaning and the fit like a charm.
For the dark color I used Vallejo Model Color Dark Grey, and the highlight is Vallejo Model Color Basalt Grey. The lighter color is Vallejo Game Color Cold Grey and the Highlight is Vallejo Game Color Stonewall Grey.