Last updated 2008.
I found this page:http://www.macupdate.com/app/mac/27034/interface-kit
But I agree with the sentiments of the reviewers: $150 is a silly price to have been asking and I would be amazed if he sold more than 5 licences.
Its not surprising that the links went dead.. probably the emails dried up years ago.
From curiosity: why are you so keen to bring on board all these UI components?
Many of the subscribers to these forums shun them if only because of exactly this scenario:
A custom class, and even an encrypted class.. if you build your app around it and the supplier gets bored or dies, where are you?
I got stuck by FireEye PDF classes that way a few years ago.
It took me months to get things working , then the author went to University and just cut the strings.
No freeware version, no support, nothing. Goodbye was all he wrote...
So I had to start again with another class, and that was painful.
If you stick to standard controls, or roll your own, or at the least have the source for an exteranl class you use, you have a chance to keep it working.
Then theres the issue of REAL constantly changing and deprecating things.
If you have an excrypted class with no support, and it contains calls to deprecated stuff, it will just die on you eventually, with no way to fix it.