I found this on a Facebook page, but a bit of Google-fu led me to the root source: Artist Scott Stadick. From what I gather this example is actually a complex 3D computer model. That said, axe-pistols were actually a fairly common item in 16th-18th century Europe – albeit one of ambiguous utility.
This video features several actual examples from history. I find the narrator’s deadpan delivery to be quite funny.
Stadick also created/rendered a really amazing pair of obsidian daggers for another project, which would be true objects of desire were they to exist in physical form.
Speaking of computer models, I have a buddy who works for UbiSoft. He has put out some feelers and might be able to get me an interview with a video game weapons-design artist. Stay tuned, it could be an interesting rabbit hole to dive down for a bit, and think of some questions you would like to ask if this pans out.
Have a great Sunday folks.