As Rob points out, it seems from
<http://gimp-print.sourceforge.net/MacOSX.php3>
that the latest version is 4.2.5.

Version 4.3.10 can be obtained by:
1. Go to <http://gimp-print.sourceforge.net/MacOSX.php3>

2. Click on "download". That should take you to
<http://gimp-print.sourceforge.net/p_Download.php3>

3. Click on "our project page". That should take you to
<http://sourceforge.net/projects/gimp-print/>

4. Scroll down to Latest File Releases and click on "download" where it
appears next to the entry for version 4.3.10.

Regards,

Michael.