I was actually surprised to read that this restoration was unauthorized. Didn't 2 Entertain announce a few months ago that it was preparing Shada for DVD release? I head about Levine's project soon after and I assumed it was being done for 2 Entertain.
Remember any such restoration would simply be an approximation anyway, and the McGann version (which I agree should be included in any future DVD) was condemned by some fans as well who felt Baker should have done it back in 2003.
Levine has pretty strong connections (considering he used to work with the Doctor Who Production Office) so I'd say we're likely to see this show up in some form before long.
As for hearing Baker do a version, I'd say cross your fingers that Big Finish manages to talk Tom and his ex-wife Lalla Ward into doing audios together. If they manage that trick, expect a Lost Stories version of Shada to be announced pretty darn fast.