Dear Herman, though it is impossible to know for sure if it is the same person without more definite information, the name Leyvik is a dimunitive form of Levi.  It is very accepted.  As for Srol it is the same.  Remember that people were writing down what they heard.  It is definitely just like Srul--dimunitive of Yisroel/Israel.

Shimona Kushner, Haifa, Israel