So after a holiday, Christmas, illness, and general laziness, I got back onto looking at the Mini this morning. I've decided to get a professional to do all the shell work, I will just do the strip down and reassembly. I'm thinking of using The Real Mini Company in Oxford.
Still trying to get the subframe off. The lower front mounting bolts (which both sheared) I managed to cut through using a saw. This allowed me to completely free the drivers side.
This allowed me to get a proper look at the corrosion behind there
However the top bolt still seems to be holding it on. I cannot see where it is still attached. The bolt sheared, but it is still holding it in place somehow. There isn't enough room to get a saw in there to cut through it.