So, does it have the Mk1 rear light mouldings or Mk3/4 ones? That's the easy bit - I was reading a thread on here about converting a Mk3 shell to a Mk1 & the changes are by no means easy. Rear window is smaller, doors & jambs are a whole different shape.
I had an easier job of converting mine back to a Mk1 Mini Minor SD (sorta) as the previous owner (read idiot) had converted a '66 car to look like a Mk4 including chopping the rear light mouldings out
Still has the mk3 lights.. so will need adaptors welding in..
Door posts with external hinges (needs new doors anyway!) etc. Isn't going to happen immediately but am planning on keeping the car so will be a long term thing!