I just spoke to a technician at TF Tuned about my forks...
I noticed in the tech manual a note that said the compression damper I have is designed to work with a specific rebound assembly. However he told be the difference is so small between the models, just a couple of shims, that any difference wont really be noticeable. He said I may lose a click of adjustment on the compression side but thats it. Im quite relived as I couldnt find the other rebound assembly for sale anywhere and wont have to fork out (pun intended) on a new one now.
He also said that in his opinion the 'open bath' RCT3 dampers were better than the newer Charger cartridges and much more reliable. Well chuffed with that news.
Meanwhile Ive made a decision on what colour to paint the frame and Im about to order what I need to finish the project.
Wish me luck!