Thirty years ago I acquired a Drummond 4" 'A-type' round bed lathe. I corresponded with Professor Chaddock, who seemed to be the 'Model Engineer' expert at the time.
I didn't use it much and sold it after a year or so.
I have a photocopy of the little handbook, a booklet of special attachments and a Drummond booklet on lathework dated 1938.
Do you want them for the price of postage?
If so. pm me (this is an expression I read on forums but I don't know how it works so I will wait to see what happens, if anything).