After much fighting to remove the original shaft - it took me nearly 15 minutes of careful(??!!) force and then some hammering and stuff too (Mine had been glued in real well or stamped in so it was a really snug fit?) - I managed to pull it all apart.
I had horrid vibrations at a certain throttle setting - right on the sweet spot for maintaining height, it would shake like mad which ended up wearing the copper collars in the rotor mount of the chassis. When I move the shaft around I can see the play that was there now.
I managed to bend the shaft forcing the rotor off so that is now useless. My first intention was to just do the CF mod. When I got it all apart and took some measurements it occured to me that with a bit of work, I could squeeze in a set of 3mmODx1mmID bearings in place of the copper sleeves pressed in there!
Using hand tools I drilled and cleaned out a 3mm hole about 3mm deep at each end of the shaft mount:
Once done I pressed the bearings in and rebuilt the rotor shaft assembly:
Man it now runs so smooth! It's very quiet, has no shakes, has much more stable flight due to the rock solid shaft and also I notice it now has smoother stepping between throttle settings - very nice! The battery seems to last longer too! My guess is there would now be less load on the motor since it's no longer fighting the vibrations!