Good but also hilarious. Presently it seems the core, modern triple-action was likely first patented by a man named Fagard. We are currently focusing on that to make sure but it is a game of gathering everything to prove a negative.
The most common rebounding, efficient system was patented by Fagnus. Though it likely went through Comblain along the way.
The whole project was started because I ran into repeated inconsistencies through various books. No one besides Muller has tried to actually trace an evolution of the revolver. Probably because the history is mostly Belgian. Muller had limited archival access and missed a good bit. We have been greatly helped by Google because we can either directly read or target and request whole lists of European patent summaries. From there we file requests with archives. Sadly many of the requested patents in Belgium have gone missing because of their bizarre filing and bad handling over the decades. We are lacking connections in Austria and Spain that would help as well.
The whole process has been expensive, we have several thousand spent on fees and more on sending people directly in to keep digging. However, we have thousands of patents ID'ed. We keep pushing them to the site at revolvers.candrsenal.com so everyone can find them.
We have a wonderful volunteer heading the organization of the raw search, so much so that if I can get a book together I am going to bill him as co-author. My job has been to analyze and pick where to focus, plus find extra help in various countries. I am also stretching to build the appropriate reference photography collection for the book.
I never meant to be a revolver expert as they aren't my favorite firearm, but the way everyone talked about them was so incredibly lacking I had to sort it out for my own sanity.