Not to disagree with an expert but I think you'll find that most of the discrepancies in Altec parts and cones in particular came from the late 70's to the end of the road for Altec. They used whatever parts were available to make the model. There are 416's with white frames, 604-8g's with and without front accessible horn mount screws etc.
I'm a big fan of Altec and have 19's and 604-8g's, both of which are the end of the trail for me.