Good advise Planet man , but my GSO Quartz actually has 3 tiny grub screws hidden inside , coming upwards to lock the eyepiece holder so it cant undo , also my sweet TMB 2 inch Dielectric has 3 inside as well but coming in from the sides , hidden under the side plates these are tiny only a about 1.5mm allen key.
I only found these by accident one day , being the consument tinkerer
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Brian.