Despite the built-in derailleur hanger, the fact that the dropouts are stamped means it's probably not a great frame. If you want to do the project as a way to learn how to build bikes from the frame up, it could be fun, and it could definitely be a ride-able bike, but I'd want to start with a higher-quality frame. Have you weighed it? That could give us an idea as to what quality steel the frame is too.