I think after the leak valve changed EVERYTHING! If anyone remembers that e3 2003 video, there was nothing in that video THAT I SAW that was in the final release of HL2. After the leak I think valve changed all their content, including the models that you speak of, after the "Big Leak".
You can try importing it to the official HL2 content now, or you could wait till the official HL2 sdk comes out. Nedless to say I wouldnt suggest it, as the models you have are Taboo in valves eyes, and shouldnt be in any new map you want to make. Besides those models that you speak of might not be up to the coding level that HL2 is at (I dont know how to model but I can immagine that something might go wrong).
Use at your own risk is what im trying to say...
[addsig]