Safe deposit boxes aren't expensive and they're not a bad offsite location to store copies of you data on external hard drives. I don't really like using hard disks for long-term archiving but it's one of the lowest cost practical solutions. A tape drive would be something to look into but they're not cheap.

When I started getting wrist pain from typing I learned to type on the dvorak layout. Your problem is probably less with the keyboard itself and more with what you're doing on it.
I also use a Model-M IBM at work and don't really care how noisy it is.. they're the greatest keyboards ever produced.

I used to have to switch back and forth frequently. It only took a second or two to get back into the qwerty mode or dvorak mode. I had the most trouble trying to type qwerty on my Model-M IBM keyboard.. because that's the touch I most associate with Dvorak.

It may be different for other people, but the keyboard touch itself helps me associate between qwerty and dvorak.

Now that I rarely use qwerty anymore, it's a little bit of a struggle to switch to it.