I am not sure what time period your are looking at, but you probably won't find the information in Worc.
Try the Clinton Historical Society.
200 Church Street
Clinton, MA 01510
978-368-0084
I believe their hours are limited to Saturdays.
I have been told they have a complete set of directories.
The Bigelow Free Library (Public) in Clinton has an incomplete set of directories.
Clinton has a very good Historical Society relative to other small towns.
Good luck.