There is a Joe Walsh vid floating around where he talks about setting up pickup height where he shows a little trick to get the double track sound on Whole Lotta Love.
You let the open string ring along with the bend. From that vid it sounds like what Jimmy did on the track. Walsh apologizes for revealing that technique too lol.
sounds really good! are you using any type of double tracking? I found this trick works well for JP Zep stuff: http://forum.fractalaudio.com/threads/stereo-tape-double-tracking-studio-tricks.105035/
i also took the factory preset "whole lotta" and tweaked the cab block. changed it to stereo hires where cab L = F18 thunderbolt (rw) with U87 mic and cab R = F34 G12H30 (RW) with 57 mic. set pans to center, dephase to 5 and low cut to 80Hz. use the bender fuzz off for rhythm's and on for leads. also cut the reverb's input trim to 50% and bumped bender fuzz drive to 1+ (to taste for solo's)