The device shown below has sat on my desk for decades, mystifying all who have seen it. It is posted here in the hopes that someone somewhere will recognize it and put a name or purpose to it. It is an enigma to us.
This device is about 3 inches tall. The yoke, band clamp and rocking strap are imprinted with alphanumeric part numbers except for the rocking strap, which imprint has been applied with a hand held electric etching tool.
The yoke is brass, the rest is steel including the ball in the tube. We assume the flat head machine screw is alien to the device. The hex head bolt on the left adjusts the devices center of gravity. The assumption being that it facilitates the setting for a standard of measurement verifying the center of balance for some shaft, turning or other construction.