Actually according the Law there is no duty on Telescopes and Telescope mounting hardware. I have posted about this elsewhere on this forums and have had a similar thread to this also. The Act, i dont recall which one makes exclusions for Astronomy optics and mounting hardware. But i have never had the opportunity to test this law.
Here is a link to my old post.
http://www.iceinspace.com.au/forum/s...0&postcount=31
Regards
Fahim