Try Rankchecker, MajesticSEO, semrush, and opensiteexplorer to see the qualities of a site.
Also check google to see if it is indexed and what sites are linking to it to get an idea of the quality of the site. And check the keyword distribution to see if SEO was done prior to the site. If SEO was done, there is probably a reason why it is being let go. Alternatively you can look into getting links from high PR domains. You can inbox me if you have any questions about that or anything really!