The script can be downloaded here. To install, copy
Copy album playcounts.scptdto your
/Users/youruser/Library/iTunes/Scripts/folder. Note that the Library folder is hidden by default. To access it, open Finder's Go menu, hold down the Option key, and then select Library. If the Scripts folder doesn't exist, create it.
Then, to use the script, open iTunes, select both the old and the new version of the album, go to the script menu () and click Copy album playcounts.
The script works by looking for songs which have the same title and was inspired by Doug's AppleScripts. Absolutely no warranty, use at your own risk. Released under the GNU GPL License.