Genealogy / THE MEANING AND RESEARCH OF MY POLISH LAST NAME, SURNAME? [4500]

Merged: Polish nicknames - Maniush and Cynab/k ???

I have some old letters between my grandmother and her cousin. Her cousin's name was Mary Pauline Mazurowski, but the letters are signed 'Manuish'. Is this a polish form of Mary or a diminutive possibly?

Her other cousin, Walter Mazurowski, is referred to as Cynab/k - again, is anyone familiar with this as a Polish nickname?
Thanks