Vintage Altec Speakers on Legs


I was at an Estate sale yesterday and saw a pair of Altec speakers for sale. They were fairly large and stood on 4 legs. The cabs were very dark and had a removable front cloth grill on a frame. The speakers were 3-way. They looked to be from the 60's. I can still get the pair for $20. They still work (they were playing music through them at the sale). Should I go back and get them, or should I stay away? I don't know the model number, although they would probably let me take the back off and have a look inside. I know nothing about Altec speakers. What should I be looking for?
spenceroo
Look for the model number on the back of the driver. The cabinet is not that relevant.
They're not horns. Just a 3 way design. Are there any particular model numbers I should look for on the speakers? I don't even know where I'd go to sell the components, and I don't want to have to sit on them because no one wants them anymore. I'm kind of going by the info I get here.