I am now convinced that absolutely everything is for sale on ebay. I did a search there and found one of the darkroom kits I had bought in 1968. I was wrong about the name of the developer - it's actually Vividol.
Of course, that raises more questions as neither my Agfa book nor my Photo Lab Index list any developer called Vividol - and a google search turns up nothing. Does anyone have anything on this developer?