For looking through your visited pages, I couldn't find any feature other than some chrome extensions that showed the most visited pages on google.
Example of some plugins that do this: Most Visited, Recent History...
You can also try looking at the google archives to see previous versions of google and copy the code or something,
Other than that for visited pages, you can easily search through the closed tabs/history page,
But not all visited pages, just most visited and history...
Regarding the reading level feature, you can see the archive file here, but there are also some chrome exertions that have some aspects of that feature. Depending on why you wanted it there are alternatives.
That's all I know about those features, hopefully it could help a little.