in what part of a report do you put the "time period of the novel"

You would put it very near the beginning. I would start with something with a bit of a hook. Consider something like,

Baroness Emmuska Orczy's The Scarlet Pimpernel (underline the title) is really a story about the first masked superhero. Before Batman or Superman, The Scarlet Pimpernel was the original masked hero who saved women and children from the horrid blades of the guillotine. The setting is........

Something like that might work. Good luck!

Actually I wouldn't use Superhero. Just hero would do (Pimpernel didn't have special powers) I would also add Zoro to your mix of examples. Pimpernel had allot of Zoro-like qualities to him.