Yes, I had a friend who used them in the late 80s. These were the other option to using Profile clip-on bars (which I used). Triathlon was a new sport then...these were used by the dedicated triathlete. Although I can't recall how these bars were mounted on the old style stem. Looks like they come apart in the front section, with the arm rest removed, so that they could be "snaked" through the stem, and then the arm rest replaced.

Dan