“But it was Jewish business owners that bought his land/city-scape paintings, providing him with a living at the time.”
Indeed, pretty much his only true friend and reliable patron was a Jewish art dealer.
I can’t recall his name, but he asked Hitler for clemency of some sort, and ended up ashes.
Samuel Morgenstern, who said they met in 1911 or 1912... imprisoned in the Łódź Ghetto, where he died of wasting in August 1943. Hitler gave an appreciative statement in the 1930s that Morgenstern had been his "savior" during the Vienna period and had given him many important commissions.