Just listened again to some of those suspect tracks and to be honest...I'm really no wiser, and either way, they really are great!

For a moment though I thought maybe Marvin had a stand in too -JJ.Barnes. He certainly could have done it he sounds enough like Marvin on some of his material.

Just my taste, of course, but the Diana and Marvin stuff is weaker, in every respect, to what went before.