osCommerce back versions, you can download from here the previous version of osCommerce.

• osCommerce 2.2 MS
• osCommerce 2.2 RC1
• osCommerce 2.2 RCA
• osCommerce 2.3
• osCommerce 2.3.1 (Latest Stable Production suitable) 

These are no longer issued via the main osCommerce site, as they only have the latest releases there.
This does not mean that they are no longer supported by the community, in fact there are are over 6,000 different add ons that support these releases, whereas the newer ones have nothing like at present, until we update, invent new ones for it.

You may also have broken your current store and need a new package to get files from, here is your place to get it from!
Select the one you want from the dropdown and checkout! Its all free.

You are also able to download the latest releases of osCommerce here.