I just stumbled on to your message board today (thanks to Google!). I think that part of the problem with finding others is that their ancestor's last names were "Americanized" when they came to the U.S. My grandfather's name became Lubich and his brother's name became Lubeck. Thankfully, my mother knew about the original spelling.
My grandfather was from Vrginmost, Yugoslavia and came to the U.S. in 1909. My mother believes that there are relatives living in Sarajevo. There was a cousin in Canada who I tried to get in touch with, but I never received a response.
As to the religion, my grandfather was Serbian Orthodox. He married a Roman Catholic girl whose parents immigrated from Suzenburg. There are some commonalities between the two religions.
That's all I can offer. Hopefully others will find their way here, also.
Linda