Mathilde Schönberg’s Meldzettel for Nußdorferplatz 5, Nußdorf, Vienna IXX
28 August 1908, cancelled 30 August 1908, Wiener Stadt- und Landesarchiv
Partly written in Gerstl’s hand, this is the registration of the accommodation to which Gerstl and Mathilde eloped after fleeing Gmunden on 26 August.
See pp. 264-266 of thesis (password protected) for further evidence and details.