Who was Isidor Thornschein?

Isidor Thornschein is not exactly a household name, but it is a name that looms large for us at the Old Broadway Synagogue. The large memorial tablet that was installed in 1947 in the men's section of the sanctuary is dedicated in his memory, as is the "Thornschein Room" as our less than elegant basement is called. Considering he was the only person in the shul who was so honored, I have always wondered who he was. This we know: Sometime in the 1940s (we would have to check the minute books to determine the precise dates), Mr. Thornschein became president of our congregation, and after he left the presidency, Mr. Thornschein became the Chairman of the Board of Trustees. Indeed, he appears (probably in these capacities) in photos from our our shul dinners from 1942 and 1946, although he is overshadowed by his successor, William Joachim. But what else do we know about him, and why was he so highly respected? He was apparently born in 1886 and according to a post on Ancestry.com, was married to Honora Ruhm, and had two daughters.

Sometime before the Second World War (most likely in the 1920s), Mr. Thornschein left from Vienna, with one daughter, Anna, and came to the United States. Now we have an unusual turn in the story. When Mr. Thornschein comes to the United States, he makes the acquaintance of an inventor, Isaac Shafran, who files a patent on July 16, 1930 for a kind of airplane and which lists Isidor Thornschein as half the assignee (http://www.freepatentsonline.com/1879857.pdf). I suppose this meant that Mr. Thornschein put up the money for this invention and was due half of whatever profits it would generate. I was surprised to see a patent application for an airplane associated with a synagogue president, but this does suggest that Mr. Thornschein was a very special individual. The next bit of evidence that we have comes from a beautiful painting that hangs in the Kiddush Room in the synagogue. No one knows who the subject of painting is. He appears to be an Eastern European rabbi, wearing traditional rabbinic clothing, in the early nineteenth century. According to the small plaque on the bottom of the painting, the plaque was donated to the synagogue by Isidor Thornschein on September 30, 1940. While we may not know who the subject of the painting is, we can make a reasonable guess as to who painted it - Isidor Thornschein himself. In his obituary in the New York Times on April 15, 1947, it lists that Mr. Thornschein was a portrait painter and was the owner of the Thorncraft Studio on East 12th Street. Among the last bits of information that we have also come from the New York Times obituary. It states that Mr. Thornschein's relatives were caught in Europe during the war and that he was trying to trace them. Were these his (former?) wife, Honora, and his other daughter? The Times also noted that Mr. Thornschein was survived by one daughter, (Anna?). A couple of years ago, I was contacted by some of his distant relatives (including a great niece), originally from Rumania, and who now live in Australia. They didn't know much. I believe that the  person who posted on Ancestry.com is Mr. Thornschein's granddaughter-in-law. I hope to find her, and if I do, I hope she will tell me more. For now, however, we are left with more questions than answers. Perhaps one of our readers knows something and can let us know?