There is an archived page for National Rotary machines at
https://web.archive.org/web/20220820...otary_Machines If you click on the thumbnails, it looks like most will open to a larger image. I tried to find a needlebar archive for the Standard company, but couldn't find.
ISMACS has some manuals for Standard Rotary machines at
https://ismacs.net/standard-sewing-m...pany/home.html