[I.C.D (Ian)]

Hi All, can anyone help me with this problem, I have a Meade LXD 75 8"SN telescope and my secondary keeps coming loose .I think it may have to do with the paper washers that fit between them metal frame of the mirror and the glass corrector plate and is not binding when tight up. I am too scared to put too much pressure on getting it tight because of breaking the glass plate.
Any ideas where I can get new washers from or what I can use instead of using the paper washers.