I'm not a Commsec user but hopefully my experience is applicable to you soundsystem. (I'm with nab-Online)
When MSC was restructured your former holding was given a new HIN/SRN. You should have received a statement from CHESS that shows your new consolidated holding and that new HIN/SRN. (Mine is dated May 10th last year)
I filled-out a transfer-of ownership form to convert the new ownership details to my old account HIN/SRN. I was also required to attach a photocopy of the new CHESS statement. Within a day or so of doing that the new holding was in my account.
MSC Price at posting:
2.1¢ Sentiment: None Disclosure: Held