Isn’t this pretty much the same as the wheel harp you posted a while ago? I liked that steampunk look better… 
I’m curious how the viola organista is powered; can’t find any info on that yet. As for the Wheelharp, I think the only conceptual flaw with that instrument (other than the visually striking but I expect rather awkward radial keyboard) is that it is electrically motorised. For good Steampunk effect it should be powered by a hamster on an exercise wheel, or better yet, a trained crank monkey.
There’s a treadle that you can see at 9:07.
Ah, thanks; I was more expecting something of that sort.
9:35 is even better.