Bought it through the refurb store - feels like new :)
The good news is that with just a few additions/changes I can build and run the Mvvm Monotouch solution in vNext in https://github.com/slodge/mvvmcross
The small hacks are:
Note that doing this needs R+W permission on that file.
Then after that, you need to convert all the portable CSProj files so that they use Profile1, not Profile104 (but back on the PC you will need Profile104 again)
To do this - replace in files, choose *.csproj, and choose to replace ">Profile104<" with ">Profile1<"
So now back to work... :)