The hens fit easily into the back of the truck and stayed quiet til they saw the rooster, then it was barnyard escapades. They were easy enough to herd into the garage, as it was pretty hot for chickens out on the concrete pad. I waited to wash & treat them til this morning, and they came back to life by early afternoon.
I discovered that the failed nuts for all the pieces had been stainless steel after all- the issue was that the foundry had welded them in too hot, and they would cool, shrink, and the welds would crack. The trick is to begin the weld on the sculpture, then feather the molten metal quickly to the nut to keep them from absorbing too much heat. Now the nuts are all either replaced or re-welded and all four corners of each piece are secure.