Hello all, I am still fascinated by the Zeffremov Kit that was available some 5 years ago.
Has anyone had any luck constructing one?

 

You're in the wrong Forum. This is the X351 Forum, for the most recent XJ models from 2010-up.

Your 2009 XJ Vanden Plas is in this Forum:
https://www.jaguarforums.com/forum/x...-x350-x358-28/

What is a Zeffremov Kit? I searched the entire Forum and Googled it with no results. You must have misspelled it.