Late Bergheil horizontal shift knob frozen

[inglis]

Does anyone have experience with a frozen horizontal shift knob on a late Bergheil where the two knobs are on the same stem?

The vertical shift knob works fine on my late 6x9 camera, but the horizontal knob is frozen.

Any secrets on how to loosen up one of these?

John

 

[Whiteymorange]

Liquid Wrench–very small drop.

 

[inglis]

Thanks!