oldest
writing style is Zaydowski
The oldest style may not be th4e morrect. The furtehr back we goi the higher the illteracy rate, and even parish priests and village scribes who basicaly knew how ot read and write were often semi-literate at best. Besides, with names there are few reuls and standards. Spelling varies not only from place to place but often within the same family. Why it chanegd from Zajdowski to Sajdowski is anyone's guess. Sajdowski could be derived from sajda, part of a weaver's loom. With names most anything is possible. Your family probably changed it to Zaydowski to make it closer to the original. Zaydoski would have been a better respelling.