Maybe i can help you. I from Poland. My grandfather is name Stanisław Szepetowski but his brother Zdzisław Szepietowski (death in England). I heard few version of this surname. Szepetowski, Szepiatowski, Siepietowski, Siepiatowski. Sorry for my english. If I can help more you pleas write for my e-mail
andrzejpew@gmail.comI see then your post is from 2003 and maybe you find this family