Fascinating and sad. I'd like to tell a similar story with a happier ending. I was looking for the first volume of JH Schroeter's observations of Mercury (published in 1788!) when I was writing my own PhD, and found it thanks to contacting a group of fans who were working on restoring and collecting his heritage in the Lilienthal observatory. All of my previous efforts had failed, but I learned my lesson here: if you want something hard to get, look for people who might be obsessed with the subject.