I've found this blog whose author, Darth Mojo, does VFX work for Battlestar: he has posted a couple entries about the old-style Cylon Centurions featured in BSG:Razor, and I believe some of the pics are new (at least I've never seen them referenced in this forum, so…).
bsg vfx: anatomy of a cylon Darth Mojo bsg vfx: anatomy of a cylon - extras Darth Mojo