Most, if not all, the P3D models in the game are ODOL format.
They have been binarized.
Oxygen can load MLOD format P3D's but not ODOL format P3D's, because they are binarized.
MLOD format can be changed into ODOL format by binarizing them.
This process cannot, as far as I am aware, be reversed.
ODOL format models are smaller in size then their MLOD counterparts, thereby taking up less room, as well as other little benefits.
So. the reason you cannot load any of the game models is because they are mostly all ODOL format.
MLOD format versions of only some of the early game models are available.
They were from the Demo of the original CWC.
I don't have a link for them but someone else might.
Planck