I'm disassembling a Petri GX-4 (aka Cosina CT-7) and having trouble getting the top cover off. I've removed the dials, levers and screws. The cover is now loose except around the self-timer switch (in photo). I don't want to force it - I'm hoping to fix an issue with the film advance mechanism and I don't want to break anything else in the process. Has anyone here repaired a similar model? #oldCamera #analogCamera #PetriGX4 #CosinaCT7 #cameraRepair #cameras #iFixit #repairs