This can take four hours or more for even short articles. All the articles in the same volume should have same font, size, leading, running heads, sub-heads, justification, kerning, captioning, etc. as well as have consistent abbreviatians, capitalizations, and print enhancements for certain common terms. All references cited in the text must be in the References Cited and everything in the References Cited must in the text. I also check spelling, appropriate choice of words, and grammar. If there are any problems or missing information, I ask the author only for the missing information.
Authors have the opportunity to read page proofs and to make changes prior to publication.
I do not mind correcting my own mistakes and adding words or phrases to clarify the meaning or to update the information. On two occasions, however, authors have then submitted totally revised manuscripts which included none of my formatting and were not keyed to the original to show where the changes were made. I will not accept future manuscripts from these authors. I once transformed a contract report into a book for a commercial publisher. The production department referred to me as a ghost writer since I had so radically changed the structure of the report to form the narrative.