Ordinance Identification

[Flying10uk]

Body diameter: 154.71 mm (6.09027 inches); Driving band diameter: 157.98 mm (6.219666 inches);

O P's measurememnts they took match this bang on I would say at 6" and 23.75"

Except that there is a 90 thousandths of an inch difference between the two dimensions that you quote for the body diameter, CINDERS, or for the younger forum members 2.286mm, precisely. Anyone who thinks that 6.09027" and 6.000" are pretty much bang on the same size is clearly not an engineer.