Sorry to take so long in getting back to you, but that evening, scumbags tried to nick my bikes and did considerable damage to my garage with 4ft long bars and hammers. They stole my wife’s bike whcih I later retrieved on an estate around the corner, lying on the floor with the wiring harness mutilated. My every day bike which is ground anchored with huge chains I thought was OK but when I went to ride it, I found they had damaged the ignition and top yoke.
Anyhow, I’ve measured my spokes and they are about 12 thous over 3 millimeters, which very nearly equates to 1/8″. My rear wheel is different than others I have seen, whilst it has an original Dunlop rim, the hub is cut out between the spokes (scalloped seems about the best description). So there is a possibility that my wheel is not original. Perhaps in 1949, they were using up stock from prototypes etc as the wheel must be lighter. I would have thought without a sprung hub or any suspension, 3mm would be best anyhow.