All historical patches are in our download area, but not linked. For example, you can get a patch to OJS 2.4.8-3 from http://pkp.sfu.ca/ojs/download/patch/ojs-2.3.3-2_to_2.4.8-3.patch.gz – and adjusting that URL you can get others. However, I’d suggest against using a patch to accomplish this as patches don’t include binaries like images. I’d suggest downloading the .tar.gz of the version you want to upgrade to (I’d suggest 2.4.8-3 for now, until you’re ready to tackle a 3.x upgrade) and following the “full package” upgrade instructions in its documentation.
Regards,
Alec Smecher
Public Knowledge Project Team