Use caution, I've learned the hard way. In general terms (if I'm not mistaken) the rule of thumb when it comes to polishing v. plating is anything a magnet won't stick to; polish and anything that does stick to a magnet is fair game for plating (providing of course a specific piece's tolerances are such that the added plating won't interfere with its function). I've been told horror stories of bottle gates coming back from plating being very attractive, but with the portion that holds the roller being "melted" beyond recognition. Same goes for the 110 linkage; there are pot metal pieces riveted to the metal arms. As such, they must be disassembled, polished & plated appropriately and reassembled. If simply plated and not disassembled and separated, one may have a little glob of goo at the end of their 110 linkage and I know none of us wants that!