I have to say that Caird’s posthumously published book on New Testament Theology is wonderful, I like his “round table” method, and it is easily in my top five of modern NT Theologies. These lectures are an entree into his contribution to the topic, and it is good to finally hear his own voice on the topic too.
Sadly, Caird never got around to writing the ICC commentary on Hebrews either, so I’m keen at some point to listen to his lecture on it instead!
I should also say that Caird’s lecture Jesus and the Jewish Nation (full text is available in the link) is the FIRST thing anyone who wants to do study on the historical Jesus should read. It had a big impact on chaps like N.T. Wright and Scot McKnight and their respective Jesus books. A classic piece that can be slowly read in about 30 minutes.