This SCP manifests as a spinning cloud of iridescent light about 2 meters tall. It manifests at the same location, but only about 2% of the time, with irregular durations and intervals. Only one person at a time can use it. When a person steps through, they find themselves at the same location in an alternate timeline with a Point of Divergence that the person was never conceived. The older the person is, the more the divergence, as a general rule. The person can reurtn to the original timeline by walking back through the SCP.
You have the item, now what's the story you want to use?
A modern successful SCP typically isn't just a report on an object, but a story in the form of a report on an object. It's not enough to just have an object, you typically need to give it some sort of significance or role on the Foundationverse, beyond just what it is and does. Why does it exist? What are the possible divergent universes? How much of an impact does just one person actually have?
If you're having trouble getting my point, I'd suggest you read more Series II and III articles, and focus not on what the object is, but what happens over the course of the article.
And no, simply rehashing "It's a Wonderful Life" in SCP form is not likely to go over well, since the story is basically cliché at this point.