Followed this up again with several people in Computershare and Commsec...
Commsec and Computershare both need to be involved and you also need a Commsec Pershing account. The process is: To move the shares from Chess Sponsored HIN to a Issuer Sponsored SRN with Computershare; then To submit a submit a CDI Cancellation AU-Canadian Register from obtained from Computershare and submitted to Computershare; then Get a DRS (similar to a Canadian equivalent of an SRN) from Computershare; then As Commsec / Pershing to move the DRS back into the Commsec / Pershing system.
Thanks to mtod for reminding me to chase this up again.
Best to check with brokers rather than just relying on the above though. I understand there are a few ways to do this and a few options depending on what one wants to do.
