Well the addon works but only extracted, pak files are renamed zips set to normal compression not rar files.
Your Sulaco size is incorrect, way too large. The Sulaco should be 385 meters and 78,000 tons(not important) if we go off the wiki.
Your orientation of the Sulaco was imported wrong, I haven't checked out the obj file in 3ds max but I suspect that is where it is wrong. I corrected this in the ship editor by rotating it properly
I don't know the info for the other ship, I can probably find out.
If you want I can fix this addon for you completely, it has a lot of issues but luckily you included the 3D models.
This reminded me I do have a couple alien ships in a file somewhere ported from Orbiter or Celestia. Perhaps I will go back to them and package it all up.