I hid quietly in the back of the shed, waiting patiently. After what seemed like hours, one came cautiously around the door. Another following meekly behind. Eventually they relaxed enough to start work, when I was able to take a quick photo on my phone!
Probably a world first, photographic evidence of the existence of shed faries! Here, they are drilling a set of engine cases to be reamed later, to accept silver steel dowels for accurate location. I managed to leave undetected and lived to tell the tale.