"This has been hanging in the barn for quite a while. Can you tune it up for me?"
Swallows or pigeons had been perching on this thing for years. It was so gobbed with guano that none of us wanted to touch it. We looked at it for a while, but we figured the customer would never pay us what we'd need to get to clean it and then address its mechanical problems. The rest of the bike was only slightly less crusty than the area shown here.
This is just one of the worst things ever brought in. The legendary Earwig Bike had been in a chicken house for long storage. In addition to various chicken residues, it turned out to be harboring hundreds or thousands of earwigs inside the frame and other spaces. They came pouring out when disturbed.