Need Bolt circle diameter of Donut

I am looking for a link to a document that states what the diameter is of the bolt circle on the flywheel on the C+E gearboxes.

There should be a picture attached of the rubber hardy disc (dounut) with a yellow circle draw on it.  It is the diameter of the yellow circle I am interested in.   I do not need an exact measurement just a rough measurement.

I am aware that the donut has a slightly larger diameter than the actual flywheel.  Either dimension is fine.