Here’s a dull one... I picked up some used Kupo C-stands. The top riser section of one is loose. It seems to be the whole ‘clamping’ section where the tightening bolt attaches which is loose. The top riser tightens fine, but there is a little wobble happening.

Has anyone ever serviced a C-stand? Is it even possible? I can see a hex bolt beneath the tightening screw, but this won’t budge when I try to adjust.