"I don't know whether there have ever been an offer from either side of a reciprocal agreement along those lines, with similar choices being offered also to non-Jews who have been exiled from what is now Israel. "


You mean that you do not look at what the state of Israel offered in 1948- It absorbed the displaced Jews, and the Arab nations could absorb the displaced Palestinian Moslims. Since Israel was a lot smaller, and had more refugees to absorb, this was a case of Israel offering one hell of a lot more than the Arabs ever did-


But the Arabs never did allow the Palestinian refugees to settle, even on the West Bank when it was under Jordanian ( you know, the Palestinian ARAB Homeland created from 77% of Mandate Palestine) rule from 1948 to 1967.