Even among the scanned books there are tons of untranslated ones. I've collected a few that I'd like to do editions of with commentaries and translations—they're all on the same topic, which up until a few years ago nobody thought existed (in fact, someone's book on a related topic denied that these existed, because the author didn't know about them). I found them all initially through scans on Google Books.

Recent versions of AI have greatly improved my ability to decode and translate ancient family letters. Finally!

Im working on this challenge with the Embassy of the Free Mind in Amsterdam… hit me up if you are interested.

Curious which books you are starting with!

Even recent works might be both unscanned and untranslated.

I experienced this when the only way to access a 70 years old scientific paper written in Italian was by finding a copy in a library and scanning it. There are not many existing copies of the journal left, in a few decades it might have been lost forever.