The first thing I do when I get a book with no copyright or publication date is to flip through the book to look for any date at all. Usually, if a date is mentioned in a book, it's a date in the past, which gives you a limit for how early the book might have been published. (When a date in the future is mentioned, that's usually clear from context. E.g., I recently cataloged a scholarship pamphlet which mentioned trying to raise funds for the 1960-61 school year, so that time period was clearly in the future.)
When I flipped through the Upton cookbook, I found an illustration with the date "1948" at the bottom. I'm assuming that this was the date of the illustration, so that tells us that the book would have been published after the illustration was drawn, so 1948 or later.
I didn't find any other dates in the book, but there were several pages of ads in the back, so I figured I'd Google the name of one of the advertisers, to see if I could find anything about when they were active.
I happened to have luck with the first ad I tried, which was for D.G. Brooks, a hardware store. When I searched for it, I found this page which gave the history of the store, including the information that the business had become incorporated in 1954, changing its name to "Brooks Bros., Inc." Since the ad in my cookbook was for "D.G. Brooks," it must have been before the name change, so I could date the cookbook to the six years between 1948 and 1954. (I guess that's technically 7 years, if the first and last year are inclusive.)
In between writing my last post and this one, a friend was kind enough to search for information about the Upton Ladies' Aid Society cookbook and actually found a newspaper article from 1993 that mentions a new edition of the cookbook being published. That article dates the original cookbook to the 1940s, which fits in with my own conclusions.
In dire situations, I've also used typography, paper quality, and other contextual clues to date a work, but it's ideal if I can find a specific date in the work, itself.