Tammy,

Try doing phonetic searches on surnames KLASSOVSKY and OLSHEVSKY at:
The JewishGen Unified Search:
https://www.jewishgen.org/databases/all/
You can search on surname only, town only, or surname and town at once, and other search combinations.

Be prepared to see the names spelled differently than you may expect.  Also, people moved from town to town for various reasons, so it's possible to find people in a different town.