[Gastraea (John)]

Hi All
I am having a bit of trouble moving the scale on my GT-81 rotator.
I just want to align it to assist in framing my image.

These scales have three grub screws but even after removing them the scale is fixed in place hard.
Does anyone know if these can in indeed by moved?
Are they just tight?

Any suggestions on how to make it budge? Gentle heat from a hair drier?

Thanks