Ian refers to a method I have found useful -- using brass tube rather than rod.
Also, instead of glue, I have had success using two part putty (Milliput, Apoxie and similar). A small rolled ball of the mixed putty goes into the hole in the base, insert brass tube, and the same on the bust. The putty goes inside the tube as well as around it and helps seal the whole mounting. If any excess putty oozes out, it can be removed while soft with no marks or harm.
The one of the beauties of this hobby is that you can do things however it pleases you.
Enjoy!
N