I would treat a third-party spam score as a screening signal, not a diagnosis. First check whether the domain has a real historical identity: archived pages, past language and topic, ownership changes, and whether it was used for redirects or doorway pages. Then review the actual referring domains for obvious link-network patterns, irrelevant foreign-language anchors, sitewide links, and sharp spikes in acquisition.
Also check the current technical state before building on it: indexation with a site: query, Search Console manual actions/security issues if you have access, and whether the important URLs return clean 200 responses with sensible canonicals. If the problematic links are clearly legacy and cannot be removed, document them, avoid redirecting the domain into an unrelated site, and build a small set of useful pages first. That gives you real performance data before deciding whether disavowal or abandonment is warranted.
