Sylvia,

I've been following your question and Angie's assistance and agree with her ideas in terms of supplying correct information in the record using square brackets, using "not..." to indicate the actual printed information from the map, etc. Any note or notes that further explain what is going on will at least help another cataloger understand should copies of this map have been distributed to other libraries. 

One of the key things you should do to be helpful to users is make sure to get a set of bounding box coordinates for the area shown on the map, this can easily be done by using the Klokan Bounding Box Tool that Angie mentioned (see https://boundingbox.klokantech.com/). If you've never used this tool one of us can help guide you. I mention all of this explicitly because geographic coordinates don't "lie" like textual information can. Put another way, because the wrong or incorrect title is on the map you already understand how a user could be upset by finding something they thought was going to be useful but turns out it is not. However, if they use the coordinates to locate the true geographic area involved they'll know immediately if that area is of research concern or not.

The other factor you can control is geographic subject headings. If you know the area involved, even if its non-jurisdictional (geological maps often are, for instance anything based on topographic quadrangles) you can figure out what county(ies), or state(s), or similar it lies within and give accurate subject headings for them. Same with classification numbers. 

BTW, I'm sure you will run into this kind of oddity again so once you work out a record you are happy with in terms of how you provided both the transcribed incorrect information and the supplied correct information it will give you confidence for the next time it happens!

Paige Andrew

Cartographic Resources Cataloging Librarian

Penn State University