Do they exist? a guy in my area is saying he has a "1972 Ampeg V4B 410" but I've only heard of the 215's and 412's myself... I've had a 76' V4 with the matching 412. Never heard of a 410 though! could it be some custom order? he said he measured the speakers and everything.. I don't want to drive out there to find that it's a 412 because I'm not interested in 412's currently.