That paper trick is SUCH a good idea! I normally bung my bits in a little box, but I like your way better.
Photographing everything is a really good idea. As might videoing be. I photographed my spring swap, but at the critical time I found I ran out of hands when changing my spring. Next time I'll video the process.
As it's a split gearbox the spring swap was easy, I'm leaving the lower gearbox just as it is until I need to mess with it.
Not that I'm chicken or anything, I could strip it down and reassemble it, easy!
Okay, maybe not just yet!