Where do you find serial number on Brunswick Balke Collender back bar?

On a Brunswick Balke Collender back bar, the serial number is typically located on a metal plate or a label affixed to the back or underside of the bar. It's often found near the base or on the interior side, where it’s less visible. In some cases, the serial number may also be stamped directly into the wood or metal components. If you can't locate it, checking with a professional who specializes in vintage bar equipment may also help.