Got the Sony DR 5A headphones off ebay for £25. They are boxed and in mint condition, with only a slight crease in one of the pads which may come out with me wearing it.
They feel like I am wearing my AKG K702s with the huge pads. The headband is plastic over metal, but is surprisingly comfortable. Sound wise, well initial impressions are like the other 1970s headphones I have with a forward bright midrange. There is very good soundstage and a real sense of stereo listening.
They leak sound, but isolate me well from outside sound.
Overall, I am very pleased with this addition to my collection.