From the Winter NAMM 2008 show:
Throughout most of Alex Lifeson's ride to superstardom with the super group Rush, a 1976 Gibson ES-355 had been by his side, both in the studio and on stage. With it, he had created many of Rush's breathtaking layered soundscapes, and the very same ES-355 continues to be an indispensable part of his live arsenal. The Gibson Custom Shop Alex Lifeson Signature ES -355 guitar is a recreation of this iconic instrument and a tribute for a true modern master, and guitar he used to expand the definition of popular music.
No more information at this point.