This 35 Elmarit and the 50mm Summicron in chrome were ‘pre-production’ [very early] versions for the original Leicaflex. Yes, not that many made and Leitz decided to go more modern black. As mentioned there are not that many (any?) Leicaflex collectors out there, so although it looks nice (I had my chrome Elmarit on a black paint Leicaflex) there just are not many folks interested at ‘collector’s prices.’
BTW, the add mentions this being a 2-cam. All early chromes were 1-cam being for the original Leicaflex (not SL), and if converted to 2-cam would actually lower the collector’s value.