ok heres the deal:
A few months ago my nut slipped and i glued it back into place with the only thing i could find....superglue

also i have a lovely red laquered finish that covered my neck...therefore i dont want to risk trying to remove/replace my nut.
heres my problem: My A string buzzes open. This is because the nut slot is too low. And, as you can see, i cant shim my whole nut. To make matters worse i have an odd bridge, in which the A string saddle is rusted solid, so i cant raise the action there....So I tried putting small metal shims (from a beer can) under the saddle height-adjustment screws...no improvement.
So, here's my question, what do i use to shim an individual nut slot?
Many thanks
Jimbob
I tried searching for an existing thread on this, but nothing

so if i've missed something im sorry! but please post the link!