Whilst doing some unrelated research of my own I came across your message. I have an old envelope posted from Heinersdorf in 1885. So there was a post office there at least. I looked in my reference books and this is in Bohemia, stamps has Habsburg eagle and postmark is of Austrian design. As far as I can tell was just called Heinersdorf (by post office) up until 1895 and then the postmark changed to Heinersdorf b. Freidland in Bohmen. This looks like Jindřichovice pod Smrkem NE of Frýdlant.