Your graphics look much more eye pleasing than before. You have addressed many of the mentioned issues.

I'd say leave it as is.

Something ready but imperfect is better than something not ready yet but aimed to be perfect. There is lots of bad cover art on the market done by professionals. It is not about to be an perfectionist but to achieve the best possible result within given ressources (time, space and money).

But for fine tuning on your next project:
Make sure that the margins do not make it appear like it is cut off because of not enough room. (The back cover art could use a little more head room.)

The picture on the cd should be centered for all elements or groups of elements.
(The picture on the cd is slightly off the center. The reason is that the picture of solid body is wider than the picture op the archtop. The ratio is about 7.5 to 8.

As David said, the gradient fill would have taken the square design to the round design.



Never the less, it is much, much better than your first try.
Guido

Desktop; i7-2600k, 8 GB mem., Win 10 Pro, BIAB 2017; RB 2017 - latest build
Laptop: i5-2410M, 4 GB mem, Win 10 Pro, BIAB 2017; RB 2017 - latest build