I don't see the problem with pulling the engine/trans and going through it to make it driveable(enjoyable). I personally would not want a rusty Hemi in my engine compartment. As for the wheel cylinders etc. who cares? you can't see them anyway. I wouldn't agree with cutting it up and tubbing it but I would clean it up and replace what is necessary and keep as much paint/interior original as possible.

Oh yeah, I would put some period correct mags and tires on it to give it a 60's street racer look.
Kind of like this one.