Unsigned Portrait – Inherited from Dutch Great-Grandmother. Possible German/European Canvas Stamp. Looking for Artist or Period Info
I’m looking for help identifying the artist or the era of this oil painting. It has been in my family for a long time, originally belonging to my great-grandmother who was Dutch. There is a stamp on the back of the canvas. It’s unreadable to me, but I was once told by someone that it identifies a town in Europe (possibly Germany) that changed its name during a specific historical period and then changed it back. I don't know much else. My great grand grandmother had it on display for many years, then it was in storage after she passed away.
I don't know where it originated, or who the portrait is of but probably a family member.
I’ve included a photo of the front and the back. I’m particularly interested if anyone recognizes the layout of the canvas stamp or the specific "style" of the portrait.