Hi redsnapper, I own a ca 1957 made Jupiter-3 ( probably with Soviet glass, not Zeiss ) and a wartime Zeiss Sonnar 5cm f/1.5, also half a dozen Contax mount lenses from before and after war, in my experience they are all good as long as there are no bad scratches, no fungus, no separation, and no tampering by people who know nothing about lens CLA.
That Ebay lens may seem a bit overpriced, but probably it works as it should and much less expensive than a genuine Zeiss in LTM. Or buy a Contax mount Zeiss, they cost less than LTM, and add an Amedeo adapter for your LTM cameras.