I’ve read Joseph Story’s writings, and early case law. Story’s writings on the subject seem compelling, and I think they’d easily qualify as “scholarly commentary”. Mr. Story himself appears to me to be arguably more qualified to speak authitatively on the subject than any modern scholar.
If you have a continuing interest in the subject, I recommend that you take a look at the development of the Supreme Court's commerce clause case law from the Civil War onwards. You need not agree with the results, but you would benefit from an understanding of how this area of law developed.
The Government Printing Office has an online edition of their annotated guide to the Constitution, which you may find at the following link: GPO Annotated Constitution