I think that it is an original damper that Howard has modified. I don't think he has a concentric headstock.Howard, something is wrong. Two videos were posted in the thread on Modified Suspension, one by Chris Launders and the other by Chris and Tracy Tilley, showing the front end working as it should. Both were on twins but the lighter weight of a Comet should not make much difference if the correct springs are used. So the question that occurs to me is what is the front damper that you are using? If you have serviced it yourself then almost certainly it is not an AVO. A lot of the old dampers had the same rate of damping in both compression and extension. That is not a good idea. Please let us know what damper is being used and then we can work from there.