The community was much larger than that, until the 1970s (many of them left after the revolution that toppled the Shah (as did many secular Iranians, and those active in leftist political parties). A Persian friend told me that he recalled having many friends and business contacts who were Jewish, and some of them had moved there from Europe in the 1930s -- others had lived in the country for generations.
He mentioned a rather bizarre incident that happened back before the Revolution. The topic came up because the trailers for the "Borat" movie had been playing, and when I said something along the lines of "of course they are totally exaggerating how prejudiced some people can be", he said that I hadn't seen the half of it. He and his (British) wife had decided to visit Bahrain on the way back to Iran from their college in the UK, and the Customs officials in that country decided to interrogate them both (in separate rooms). The ordeal lasted for several hours, and when they were finally released, they were so rattled that they decided to skip their visit and go home to Tehran. His wife told me that the officials accused her of being an Israeli spy (based on the fact that her middle name is "Sarah") -- in vain, she tried to explain that names from the Bible are quite common in European countries and colonies. The husband said that the officials were openly contemptuous of his Iranian passport: "You're Iranian! All Iranians are Jew-lovers ... you even let Jews out in the street, in Tehran!" So even back then, there was tension between Iran and some of the Gulf countries.
An article re: Iran during WWII
"As early signs of the murderous Final Solution became visible in Europe, the Iranian government of the time convinced the Nazi race experts in Germany that Iranian Jews had lived in Iran for over 2,500 years, and were thus fully assimilated citizens of the Iran and must be afforded all the rights of such citizens. The Nazis accepted this argument and the lives of all Iranian Jews living under the Nazi yoke were saved. An account of this episode can be found in the "History of Contemporary Iranian Jews," published by Center for Iranian Jewish Oral History.
Moreover, as I have recounted in my book "Persian Sphinx," Iranian diplomats in Europe and elsewhere offered hundreds of Iranian passports to European Jews, thus saving their lives. And when the Nazi killing machines began their slaughter of innocent Polish Jews, 1,388 Jews, including 871 children were moved to Tehran where they lived in relative safety till they moved to Israel. Again the "History of Contemporary Iranian Jews" has provided an account of what are called "Tehran Children.""
http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2006/02/19/INGMQH9TVM1.DTL