Peter Laidler spent some time writing 4 articles on setting up a 'clone' No4T and, much of it, in great detail on fitting pads and collimating the scope.
They can be found here :
Part 1 : http://www.milsurps.com/content.php?...ter-Laidler%29
Part 2 : http://www.milsurps.com/content.php?...ter-Laidler%29
Part 3 : http://www.milsurps.com/content.php?...ter-Laidler%29
Part 4 : http://www.milsurps.com/content.php?...ter-Laidler%29