One of the Library Patrons found the missing issues of the 73 Magazine Category
the 3 issues from 1960
the 1961 issues
the holiday issue from 1976
Thanks a lot!
p.s. I spent most of today (Saturday) working on the Scientific American Collection. Having to check each volume for missing issues and then download and rename those so they all have consistent names. Made it through Volume 3 of the 99 volumes.
Fortunately only a few of the volumes are missing issues so most of that was working out efficient procedures for building the catalog as I go.