Per the Chicago Tribune: “Dali’s owner, Singaporean firm Grace Ocean Pte. Ltd., and manager, Synergy Marine Group”. So, start there.
And, taking your point that Maersk is but a cartage customer and has no financial liability is concerning.
Of course there is also this, from Business Insider: “Owner of ship that crashed into Baltimore bridge will likely try to invoke 1851 law used to cap damages after Titanic disaster”
the law you referred to limits the ship owner’s liability to the value of the ship at the time of loss, the value of the cargo lost and any proceeds earned on that voyage.