Pretty basic newbie question here, sorry
When I finally get around to washing my 202mm GSO mirror and most probably wash off the ring binder circle (unintentionally), is the "bottom" (centre?) of the paraboloid close enough to the geometric centre of the mirrror, so I can relocate it and re-attach a new centre spot. I'm guessing these mirrors are designed so it surely must be within a mm or so of the geometric centre otherwise things would start to go wrong in the image path?