3.0d engine and purchase queries

Hi All,

I am going to see a 61 plate (pre-facelift) XF S 3.0d today with a view to buying if all is well.  Total mileage on the car is 125000, 1 owner with all service and repairs carried out by jaguar.  The engine was replaced by jaguar in 2016, so the new engine has approx 70000 miles on it and the timing belts have already been changed  (I think the owner went off the odometer reading as opposed to actual engine mileage).

Anyway, does anyone know if the replacement engine in 2016 would have been any different to the 2011 engine?  In terms of improved components for common failure points(eg inlet manifolds etc).

After reading a lot about alternator failures, does a new alternator come as part of an engine change?

I am slightly concerned that the replacement engine is approaching the kind of miles (70k) where it starts to suffer faults.  Is there anything in particular I should look out for?

On my list so far is:

Check all the door locks, Check for water ingress in boot, Check all electrics work.

Thanks in advance.