I took the leatherette off my very battered RB67 last year and replaced it with thin leather, feels a lot better in the hand and looks a lot tidier, only took an afternoon to strip down the body, cut and glue the new leather, only cost me about £10 for a sheet and i still have enough to cover it at least twice more :)
I used Micro-Tools for the leather and Pliobond :)
Replaceing the leatherete is quite easy on an RB without removing the focus knob. The only part I see you'd have to remove is the flash mt and the neck strap lug nuts so you can get under em.
Micro tools n some other sources on the net have the stuff in self stick n many colors. Use the old leatherete as your templates n have fun.
I hope you'll post some pics of the finished product?