Not sure what "murco" is, but I would imagine that the company in which he held the stock would have record of its shareholders and transfers. Of course, if he has a broker, check there first. If you initiate a civil suit, you can ask questions of the wife under oath (sounds as if they are estranged). You may be able to file a crimminal charge as well if there was fruad involved.
Also, see if FINRA, the securities regulating body, has any ideas. Link included.
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