I don't know about that vintage of Speedaire, but these days Speedaire is owned by Grainger. They're darn good compressors. Mine is a 20-gallon, rated for continuous duty, single phase, workhorse. Completely made in the U.S. Cast iron pump and a Dayton motor.
The only thing I'd be concerned about with one that old is if the tank has any weak spots from rust. An exploding compressor tank is no joke.