I have a pair of black ones that were last fitted to an 82 GoldWing, so they should be trimmed correctly for the 81 as well. I am not certain they are a type 51 though... they are definitely for a WJ V though. I am looking to get $120 for the pair and that includes postage. Looking on fleebay, they ar asking about $90 per side plus postage. If interested, let me know.