I am reliably informed that she was Blackpools adopted ship.There is a superb model of her in St.Johns Church,Church Street Blackpool Centre.There is also a memorial to the ship.Apparently the plans for the model were obtained from the Blackpool Council! May be worth a try!
The Imperial War Museum has plans in their archives,which are probably the most comprehensive you will get,but they do not come cheap.
Good Luck
Mick F