Here are some helpful resources I thought you might find helpful. I came across when researching this book.

Assessment Tools

National Communication Association Resources on Assessment

Assessing Motivation to Communication: Willingness to communicate and Personal Report of Communication Apprehension. National Communication Association
https://www.natcom.org/sites/default/files/pages/Assessment_Resources_Assessing_Motivation_to_Communicate_2ndEd.pdf

The Competent Speaker Speech Evaluation Form. National Communication Association https://www.natcom.org/sites/default/files/pages/Assessment_Resources_Competent_Speaker_Speech_Evaluation_Form_2ndEd.pdf

Open Source Public Speaking Textbooks and Free Resources

Advanced Public Speaking https://uark.pressbooks.pub/speaking/

Boundless Communications https://courses.lumenlearning.com/boundless-communications/

Communication in the Real World https://open.lib.umn.edu/communication

Communication in the Real World
https://lor.instructure.com/resources/34046bad87cf464c87e98bcfe97647e9?shared&fbclid=IwAR0dOtx4AqYQkYIj5_JKB8v3YjbUYJCSWUbIMgX3T8xSN2Dn1C8HlApjmfI

Exploring Public Speaking https://open.umn.edu/opentextbooks/textbooks/411

Exploring Public Speaking https://alg.manifoldapp.org/projects/exploring-public-speaking
I included two links since each mentioned a different second author.

Introduction to Public Communication. http://textbooks.whatcom.edu/comm101/front-matter/title-page/

Presenting Your Research: Conferences, Symposiums, Poster Presentations, and Beyond. https://ebookcentral.proquest.com/lib/uark-ebooks/detail.action?docID=5613668

Principles of Public Speaking https://courses.lumenlearning.com/publicspeakingprinciples/

Public Speaking Basics, https://ebookcentral.proquest.com/lib/uark-ebooks/detail.action?docID=2010988.

Public Speaking Practice and Ethics https://2012books.lardbucket.org/books/public-speaking-practice-and-ethics/index.html

The Public Speaking Project http://publicspeakingproject.org/

Toastmasters Resources

Inspire Your Audience.
https://westsidetoastmasters.com/resources/powerspeak/toc.html

YouTube Channels Dedicated to Public Speaking

https://www.youtube.com/channel/UCgrhMB4iEHdwx0qdgiRcX2w

https://www.youtube.com/channel/UC2E0r-kYhpUlfVxqemrDSoA 

Professional Speech Coach Websites

Science of People https://www.scienceofpeople.com/public-speaking-tips/