This is a very interesting piece of work. Quite a few of these collections of notes, that were never really intended for publication, did get published anyway. Wittgenstein’s Zettelkasten is one of the more famous of them.

It seems unlikely that Innis’s ‘idea file’ will be republished in the form of the original index cards. According to the introduction to this book, they’ve probably been lost. More at The lost notes of Harold Innis