I recently pulled the front corrector from my newly acquired used Meade 12 ACF OTA to clean it up a bit and noticed that one of the cork shims that holds the corrector in place in the front cell was missing. I'm sure the seller had no idea this was going on. I noticed that this allowed the corrector lens to move around a bit and not stay firmly in place. Can this shim be replaced with something similar? I assume this corretor movement might affect the alignment of the primary and secondary mirrors a bit as I noticed when I checked collimation the other night the in-focus rings were perfect but the out-focus rings were off a bit. Saturn was kind of blurry but as the night went on, the images of globular star clusters at medium and high powers was pretty good. How would you check primary and secondary mirror alignment without and laser or other collimation tools? Do I need to send this to someone like Company 7 to have it done properly? Is there anyone else I could contact if necessary? Thanks for any help/feedback.