He probably used a signet ring to mark his letters with een seal stamp. A stamp of his ring can be found in the archives of Arnhem. Since Johan Joseph had no children, his ring was probably heritated by Gerret Willem Christiaan, the son of his brother Willem Christiaan. Gerret Willem was a chemist in The Hague. Gerret Willem van Dort was granted permission by the queen to call himself van Dort-Kroon.
Kroon is Dutch for crown.
Hence his children are all called van Dort-Kroon. Lijsbet van Dort lived in Delft. It also has a crest gold and red, mantling gold, red. Lijsbet Jansen van Dort was married to Jacobus van de Minne. Here you can find a copy from there mariage certificate .