You can pull out all the mods from those pieces before RE them. As for the armoring - you may put it only in the same gear slot, for example leg armoring can be placed only in legs.
When you RE campaign item, you may learn schematic for orange item with the campaign item look. It is empty, without any mods. Just like any other orange.
As for the mats for those orange items - they drops and can be found in boxes in Denova.