Would preserving the Canadian Diadem-class cruiser discussed here create the largest museum warship?
Short answerNo. At the stated 11,000 tons, she would not be the largest.
NotesPreserving the Canadian cruiser would be welcome, but it would not make her the largest museum warship. The comparison identifies an 11,000-ton Diadem-class protected cruiser. The individual ship's name is unclear in the captions.