>>/45643/ One of Robert Mueller's brother's was named John Freeman Mueller (UNSR). This guy on twitter did some digging on him.  I confirmed the name was real through an old wedding announcement. I know he was in the navy and stationed in California based on other articles.  This guy on twitter posits that he was building aluminum submarines.

https://twitter.com/HousatonicITS/status/1108903997849645056

https://www.ussnautilus.org/the-aluminum-submarine/