You got it spud, cheers

The larger OD pulley would mean a slower fan speed, wonder why they went that way? How much would it affect cooling?

D ports were all about power so slowing the fan would mean less power consumed by the fan and maybe they set the dia so the same fan belt could be used.  I wonder if this was also when they introduced viscous fan couplings.

Stand corrected Spud. They do look like completely different pulleys. Offset will be the same with each setup though? Dport and pulley or oval port and pulley will leave the belt in the same position? Yes.

Yes that's right- offset is the same

Re cooling, I've never run fan blades on my old cars inc the V6 Capri and always runs smack in middle of Temp Guage with a 82C Stat and 33% AF/AB Coolant Concentrate : 66% demin water.
Will fit Fans one day with a switch as I'm sure "Murphys Law" will get me one day in heavy stop/start traffic, deluded that I'm always travelling on traffic-free Peninsula roads..............or to ALBURY Capriciation !