The ut2003-2136source.zip file you have requested: Official Releases / Patches / UT2003 2136 Source Files - 9.59mb is not available. Perhaps try browsing all files for the game Unreal Tournament 2003 and upload any files you want to share or are missing. This is the only information we could locate:
These are the updates to the source files released with the retail game. Just unzip them over your existing SDK (you are going to make a backup first aren't you?). Be aware that there is a new UDE in this package also.