Can't edit my last post. That should be the manual for
Eldredge Improved Rotary B manual on the ISMACS link. It will give an error if you try to open in new tab, but if you click on the name, it will open it in a new tab. There is also a B long shuttle, which won't help much. As far as dating it, I'm not much help.
PS looking at the tumorfarmer blogspot link, it indicated was like a Damascus Grand. and there is a manual for it at
https://archive.org/details/instruct...chine/mode/1up