In the case of Ab.67.13 L’Etourdie, ou Histoire de Mis Betsy Tatless (Berlin, 1755) the Bavarian State Library (the Bayerische Staatsbibliothek) in Munich held a set in two volumes in 1934, which was reported by Mary and Lawrence Price, but only the first volume survived WW2.
In the case of Ab.67.17 Geschichte des Fräuleins Elisabeth Thoughtleß (Leipzig, 1754) the Berlin State Library (Deutsche Staatsbibliothek) in Berlin held a set in two volumes in 1931, which was reported in Gesamtkatalog der preussischen Bibliotheken, but only the second volume survived WW2.
(The Prussian State Library i.e., the Preussischen Staatsbibliotheken only existed between 1918 and 1945; the library was broken up with the partitioning on Berlin and the collections were not reunited until 1992, only a few years before my visit. See Wikipedia entry here.)
I was struck, at the time of my visits, by the symmetry of these random losses, the first volume of one set, the second volume of another. And I was reminded of these losses this week by the happy discovery that Staatsbibliothek zu Berlin has acquired a second set of Ab.67.17 to replace the set "keine Benutzung möglich." And, ever-zealous to make amends for the past (past destruction wrought by and on them), the Germans have published the whole thing online (here) in colour.
The interface is a little clunky but, as you can see, the images are clear, the printing is gorgeous, and the digital facsimile is complete: including the binding. I have a link to this facsimile on my page of links to Haywood texts and scholarship—it is the first such link to a text not on Google Books. I hope this is a sign of things to come. That individual libraries will move beyond the production of online facsimiles of the same small number of prize texts, to facsimiles of a substantial portion of their historical collections.
(Keeping track of all the texts published online this way might be a challenge, but I'd rather have the challenge of finding all the texts I am interested in online, than be forced to fly to the other side of the world and undertake a nearly-endless trek from library to library. It is not that I didn't love the opportunity as a student to see so much of Europe and America, but it does seem mad to spend five minutes looking at one book after another, at one library after another, in one country after another, for months on end, only to return home and discover that—since I had overlooked a handful of tiny details—that I have to repeat my journey to complete my study!)
[Deutsche Staatsbibliothek copy 2 (19 ZZ 11623)]
[UPDATE: 2 July 2016: After all my pictures disappeared again, I decided to give up on external hosts for large versions (1000px) of my image files, and will stick with the smaller images (500px), which Blogger is prepared to host, for now on.]