Margin Report for OSCommerce 2.3.1.
Based on the Margin Report v3.00b (french), which can be found here:
http://addons.oscommerce.com/info/1594
I basicly modified the necessary within the installation instructions and included margin_report files so that it works within OSC 2.3.1.
I have no issue what so ever in using it, but seen my small knowledge on the PHP side of programming, I won't be able to give you support.
Use the official support topic for questions.