This first part is a little thin – I think I’ll use it and it’s partner to figure out the mounting and general fit, then I’ll layup the final parts.

I thought I would use these first layups as the final product.  Due to the shape of the plug I couldn’t get the first layup off without sectioning it, which damaged the plug some.  So I think I’ll put the plug to one side and use these first layups as molds for the finished item.  The inside surfaces of the layups are almost perfectly smooth.  Any layups from these molds are going to need very little filling and sanding before painting.  In the last image I’ve added flanges around the mold halves so they can be clamped together for the layup and then separated to release the part after it’s cured.