There's a simple way: download the SRC RPM and open it with 7z (which can open .rpm files without being able to modify them)
You will find in it all you're looking for: a .tar.gz which contain all files that will be added during the RPM install. Directories /opt and /etc/e-smith/template/etc/httpd/conf/httpd.conf are good start points
You will also find a .spec file. Open it with your favorite text viewer - that's the 'install script'. A lot of stuffs are in it and if you can read a little bash code, then you will quickly understand the whole stuff!
Create a new template - let's say 96Mediawiki2 - and paste the content of the original template (or update the one created by the RPM install)
You can't install it in /opt/Mediawiki because there's already one install running here, so why not installing it to /opt/Mediawiki2 or whatever and don't forget to update paths in the httpd template everytime it's needed.
You just need to change a few other values.
As I told you the Aliases couldn't be the same (look in the httpd template to change both aliases). LocalSettings.php must be updated with new aliases too. Why not choosing mediawiki2 and wiki2 ?
You can use the same MySQL user/password created by the RPM install, But creating a new one is better... Adjust user/password in LocalSettings.php when done.
You must create and import the prepared database in a new database (or at least use different prefix if you want to only have 1 database for both websites)