And why exactly would you redirect a working (well aged) domain with rankings to an entirely new domain with a .mobi suffix and no rankings? Just for the extra related keyword in the domain?
Don't do it then. You're making a big sacrifice for nothing. In my experience, .mobi domains don't have that much value as .com domains (no hard proof of this). The new domain also has some issues apparently. I won't start from zero on this one.