Original is metal and will last, paint is poor quality and thin if it scratches off down to metal simply installing a clip which can be done carefully. If trim is original it suits metal clips best. The reproduction trim, which I haven't used, can use both but some of the horrible curves need the plastic clips. So a handful of both can be of use, or at least a few plastic thrown in if there's a problem area, but that's generally only for the repro trim. I've bought more metal clips for spares, blackened and plated, but haven't reinstalled since. Even GM replaced some of their original metal range with the nylon alternative in later years, probably cost less.