I just picked up a second pair of 19s circa 1977. One cabinet has a 416-8B, and the other has the driver in the pic. It has the same frame as the 416-8B and my other 416-8C, the cone is stamped 211844 which I believe is the correct cone for the 416. The only ID marks on the magnet is a square ink stamp that says AL with 64 underneath. I'll assume that means AlNiCo unless somebody corrects me.
I'm trying to figure out what this is. Is it a 416-8B without the cover? A 416-8Z? I'm hoping these two drivers will work together without having to go on the hunt for a new donor driver. I already feel like an idiot for not catching this before the purchase.