Well done Hedy! The digitisation of rare books will enable us to study at home. I'm also very happy about that.
I do not know if noticed that Dr. Gertlieb Gmach issued an interesting book in three parts from 2014/16:
"Österreichische und ungarische Posteinrichtungen in den Donaufürstentümern (Rumänien) : (1782 bis 1880)"
– 1. Historisches Umfeld, Begriffe, Postwege, Desinfizierung, Postorte, Stempelkunde. - [2014]
– 2. Konsulatsposttarife, Auslandsposttarife (1836, 1844, 1851) je mit internationalen Korrespondenzen, Postverträge, DDSG, Lloyd. - [2015]
– 3. Postverhältnisse in der Zeit um den Krimkrieg ab 1853, Telegrafie, Exkurs zu Krajova, österreichische Währungsreform 1858, auch im internationalen Kontext (z.B. DÖPV, ÖIPV und Risorgimento, fremde Staaten), Soldimarken ab 1864. - [2016]
I do not have these three books but I lent two of them (part 1 and 2) from the Philatelic Library in Munich some month ago. These books are describing postal routs and the disinfection of mail very detailed. The Austrian cachet you mentioned is also illustrated and it is mentioned that it was used in Schuppanek (Supanek, Zsupanek). The author also stated that the quarantaine station Schuppanek was erected based on an edict of 1775. Especially during the revolutionary movement of Tudor Vladimirescu in 1821/22 Schuppanek was used to disinfect letters because the normal postal route from Constantinople to Vienna via Bucharest was closed and mail was sent via Cernatal.
Kind regards
André
P.S. The author Dr. Gmach is referring to the following article: Cserni, Carantiniele din Transilvania si Banat, Filatelia 2004 (magazine no. 3 and 4)