Wow, that is the second worst port job on an Eaton blower I have ever seen! Some people just should not be DIY'ers.
By the way, the entirely worst "port" job I ever seen was when some genius of airflow dynamics decided that since bigger has always got to be better, that he would mill out the entire bottom of the blower case. To add insult to injury, he also polished the inside of the case where the rotors spin as well because he "thought those scuff marks looked bad". Made a nice boat anchor after that.