I would also like to have possession of the material to try to finish this project, but I did not get an answer from the author and given the past time, maybe everything no longer exists.
To make my Age of Horror add-on, I posted a request on all sites that contained information, addons or Mods created for RTCW, but very few authors responded.
My intention was to make a project containing 30 levels, but I only managed 16.