Indeed, these records were cut direct-to-disc.
The process used was beautifully demonstrated and filmed on the recent American Epic PBS documentary, URL here
https://www.pbs.org/wnet/american-epic/
Look under "American Epic Sessions". This shows modern day artists (like Jack White, Elton John etc) all recording direct-to-disc on 78rpm using the last surviving mastering machine of its type.
The process used was beautifully demonstrated and filmed on the recent American Epic PBS documentary, URL here
https://www.pbs.org/wnet/american-epic/
Look under "American Epic Sessions". This shows modern day artists (like Jack White, Elton John etc) all recording direct-to-disc on 78rpm using the last surviving mastering machine of its type.