One way to expose your current readers to the older stories on SOL is already being done, you show the name, author and other details about older stories almost as if they were currently posted. The blast from the past stories are refreshed at intervals, maybe every half hour? So there is almost always something new that is old whenever a reader logs in.
My suggestion is that something similar be done with older reviews. Celeste, for example, has some of the most readable reviews that nearly every reader might like to review when it came up. Not just for the story but for her thoughtful analysis. I understand anyone who is interested in reviews can already find them by clicking on the reviews button, and one way to tell if I might be interested in a story is by reading the details and then, if there is a review attached to the story, clicking on the review. However I suspect reviews are far less popular than stories. On the other hand (am I running out of hands?) you already present older stories that might find an appreciative audience and I suspect it runs without a lot of work by you, once the system was set up.
Can you use the same software or an easy to program version of it to bring back past reviews? Other than forcing people to go back in the author or story files to find something old in order to read something new, I don't see another better way to bring older stories to the attention of new readers. Clearly that is one of many objectives of the site, to bring all the 38,000 stories stored here to the attention of more readers. Perhaps someone will have another, better solution than the brute force of starting with authors whose names begin with A and looking at all the stories on the site. Older stories that some past reviewer liked enough to write a review about might be one way to accomplish this mission.