I followed this route too. Since I don't need the last Wolff unpublished picture. His cover pics are more than enough for me. And in this respect I've a very good and very recommendable BN cover book I got in the early 2000s, I think. It's called The cover art of BN by Graham Marsh and Glyn Callingham, but I don't know if it's still available.
On the other hand I also have the right one from this picture, which I got heavily discounted from TrueBlue. This book I don't like so much, because the pics are mainly color, from the late sixties, as mentioned above (I assume it's the same book). And I don't think this period is the most interesting in the BN story (Hank Mobley in a turtleneck sweater). And it's not very well bound, pages are already falling apart.