I'm not experienced with the rivco ones, but I do know that when I bought the NEW triumph ones I was very impressed, very sturdy, and better welds and deeper chrome then the ld ones. felt more substantial too, and no flex when I use my highway pegs like the old ones.
the older version had welded on tabs at the end of the bars to mount, the newer ones have a gusseted mount welded on the end thats 100% better, definitly worth a look at if you cna find a set to see
the older ones were kinda flimsy thats for sure,