Perhaps, but not that easily. You'll have to convert them into .md3 models, and that might be a problem, because they have a size limit. Also, base JA doesn't allow models that have more than 1000 vertex per mesh, for an absolute maximum of 32 meshes per model (if I remember correctly). And even if you were to successfully convert them, you'd have to put them into the map through Entity Modding, and adjust the scale properly. And even then, most likely the models will be fully lit, and won't be solid - perhaps they might be with the q3map_clipmodel line in the texture shader, but that's only a wild chance. In the end, it might not be worth the price.