Korn GENTILES, THE WORLD TO COME, AND JUDAISM: THE ODYSSEY OF A RABBINIC TEXT
Modern Judaism.1994; 14: 265-287
Michel S. Nehorai, “Righteous Gentiles have a portion in the World-to-Come, Tarbitz 61 (1992), pp.465-487
Steven S. Schwarzschild, "Do Noachites have to Believe in Revelation?" JQR, 57,.
4 (April, 1962)

I haven't seen it yet ($), but R. Alan Brill's new book likely has additional sources, I have another list I will have to add and post. Here is a translation by Yaakov David Shulman of the central text of Rav Kook in Korn's essay with an additional note on the meaning of "olam haba";
http://www.shemayisrael.co.il/parsha/review/archives/bo62.htm
I also did a post on this Rav Kook that extrapolates to other similarities between after'life' experiences and phenomena accounted by non-Jews;
http://harherem.blogspot.com/2006/10/recent-editorial-to-moment-mag-letter.html
There's also the famous Tiferes Yisrael on Reuchlin and Jenner - not conscious abiders of the Sheva Mitzvot as far as history accounts - that can be found translated here (search);
http://www.scribd.com/doc/20065780/Rabbi-Jonathan-Sacks-Dignity-of-Difference-Sources-in-Traditional-Jewish-Literature
Posted by: pierre | May 05, 2010 at 09:56 AM
A very powerful piece by R. Adin Steinsaltz I believe I may have posted before regarding Sheva Mitzvot and religions extant today;
http://commonknowledge.dukejournals.org/cgi/reprint/11/1/41.pdf
Posted by: pierre | May 05, 2010 at 11:16 AM