A massively updated version of "Mul-T-Lock: Design and Security" is available on LockpickingForensics.com. From the site:
This paper discusses Mul-T-Lock telescoping pin-tumbler designs throughout the company's nearly 40 year history. This includes the Classic, Interactive, CLIQ, 3-in-1, MT5, and MT5+. In addition, attack techniques against Mul-T-Lock systems are evaluated. There are several appendices that include keying and coding information for Mul-T-Lock locks, as well as a patent reference for (almost) all Mul-T-Lock models and components.
You can grab it from the articles page, or via the direct pdf link.
I can (attempt to) answer any questions you might have here or via some other form of contact (contact details are available in the paper or on the website).