Battradio, it looks like a circa 1945 or 1946 model 515 from one of the early Voice of the Theatre systems. It will be worth more to a collector if you can retain the phenolic spider and original style cone. These drivers are sometimes called 515A, though AFAIK Altec never gave them that designation.

Now about that 1400 series RCA woofer the 515 is sitting on... yum!