Got this reply from OSC. Might help someone.

"Thank you for your inquiry to the Ontario Securities Commission (OSC) concerning Crystallex International Corporation (Crystallex). You would like to know what can be done to ensure these shares remain in your account, in the event that Crystallex begins trading publicly again in the future.

As you may be aware, Crystallex has been the subject of a cease trade order (CTO) in Ontario since April 13, 2012.  A CTO is typically issued when a reporting issuer has failed to make timely disclosure and shares of that company cannot be traded until such time as the company files an application to have the CTO removed, brings its filings up-to-date and pays outstanding fees.

.... With respect to how you should proceed, you may wish to follow up with the firm where your shares are held to see what your options are at this time,."