Thank you for the valuable information the disassembly went well and the mirror cleaned up like new. I've replaced the grease, with just the bare minimum. I used high temperature axle grease, that's all I had anyway and it's red just like the stuff that leaked out.
But I need clarification on the direction of the black line. If I hold the mirror so that it's facing into the telescope the black line can only face the focuser knob side (my left) at the 7 or 11 o'clock. It could however face away from the focuser at 3 o'clock. Or should I be placing the black line pointing at the focuser when I'm looking at both the mirror surfaces.
Thanx again Peter
Just a after thought on this. When the scope was new the secondary cell was loose and it was repaired under warranty and was tightened so that the Celestron label was horizontal. Was this correct ??