I've been a great fan of the "In The Round" photography technique for a good while now, but I have only rarely attempted it myself, with mixed quality in my results. That being said, I did this composite yesterday from sixteen frames. It was a little more challenging for me than the typical subject as it wasn't symmetrical, but I think that the final result was still worth sharing.
Nice work Matthew, looks like you have the technique figured out.
One thing you could try…., Ventosa himself tends to retain a level of detail in key areas of the image. In this instance I think you could add detail back in the church window by way of duplicating an appropriate layer and using masking/opacity to taste.
Just something to think about. I have used this technique many times myself to bring back a little detail where needed.