I finally took a few more pictures of it, here it what it looks like in use.
The only picture taken with it I have online is, I think, this one, one of my first successful photos with this rig :
Bee gathering thistle pollen | One of my first experiments w? | Flickr
I have a few others on my hard drive, I could see if I manage to find another one.
As I said, it is not the most practical rig, due to the extremely short working distance. But it does the trick, provides nice, even, but still directional light. It is also fairly compact due to the horizontal flash arrangement.
The hinged flash bracket is a piece of junk though... You have to tighten it with such force that it is really difficult to loosen it without pliers... Even then it does not really stay in place. I did not find any other solution for this, unfortunately. Maybe I should just glue it in place, as I always use it at the same angle. But I'll have to see the angle I use with my DFA 100 macro WR.