Thanks for the information, everybody. I'd like to hang on to the holders, but could use some extra cash to get some various repairs done. I will be selling the holders. I gave the enlarger away to a friend for whom I set up a darkroom. I will probably try to get the Yashica unjammed and keep it as a "car camera". The two Vivitar lenses for the Nikon are also going to go (cheap). The Nikkor-S is trash due to its badly marked front element. I might try to take it apart and tweak it for soft focus or something like that, but it is probably just a paperweight or a parts lens. One guy e-mailed me already about the holders. I wonder what they are worth.