Google has a very long memory. Just because you don't see it in search, doesn't mean it's not indexed. You should not use duplicate content like this if you care at all about the site.
And if you like you re-register the expired domain which content you want to use then redirect it to your new site. The cost is just what you would pay for 1 500 words long article- $10/yr.![]()
Pick a few lines from the content and search it in Google using quotes: "This is an example text.". If you see any results, it means the content is still in Google's index and you can't use it. If you get no result, feel free to use it.
You can use expired content, I've done it a lot over the last few months. Everything is fine.