Mine is "drivable" but far from road worthy yet. I have the watts link for the rear all mocked up and ready to install, but kids and work have kept me from doing much the last few years.

I would stress originality over a late model driveline. At worst, if the original engine is a seized block of rust, you maybe able to put an m189 from a 63-up 300se in there. The rest of the original driveline can't handle the torque of a v8.

Wait until you get a chance to see the frame in the thing. It is one massive hunk of steel. I can't fathom what it would cost to build an equivalent car nowadays!