AR 1 was built around the highly regarded and highly coveted WE/Altec 755A.
Well preserved 755A's can bring up to 2K for a pair. They are indeed "special" and IMO, perhaps the finest sounding "full range" speaker ever made.
This one will take a hit for the dented dustcap, it's also a later Altec built 755. Early AR-1's will have 755's that are Altec labeled, but were built in the Western Electric factory, these are the ones that get the "atomic" bids. WE built 755's will have 6 welds attaching the return pot, the Altecs have 3.