To be a little more 'e-smith' friendly, I'd suggest doing the following:
mkdir -p /etc/e-smith/templates-custom/etc/rc.d/init.d/masq
Then copy whatever files you want to modify from the 'original' templates folder to this new one.
Make your changes and then do the normal template expansion jig.
The template engine will take any files found in the custom template folders over the standard ones, so you changes *will* make it into the built files.
That way, if you stuff something up, you can just delete/move the custom files and the template engine will go back to the originals.
Luke.