This is a good task you are working upon. However, I'd say that almost all of CS:CZ models are interesting but have missing faces. I'm sure people from the Ritual Ent. dev team and people at VALVe themselves might have the originals lying around somewhere with all faces intact and textures set at original resolutions.
If you compare models from Deleted Scenes (Single Player) and CS:CZ, you will note that the textures were made slightly better while introducing the earlier CZDS models into CSCZ but they were cropped in half though.
Hence even for this project, you should be using the CZDS M4 which has HD textures rather than CZ one.
you should make it make it more hp than should be because it will look bad ass!! for example in the handguard part,stock and several part there...and ensure to smooth it well... also please do the same when you end with the cscz ak47...