Thought it would be good to close out this thread with a couple of pics showing the job done.
I finished up getting a Gates water pump as the easiest OEM replacement option. Not much to see but an easy straight replacement.
Had toyed with the idea of a black pump for something different, but at over three times the cost and also possibly making it harder to see issues, I opted out.
Only issue I reminded myself of was the lack of belt clearance to the main lower inlet hose to the pump. The old hose had some slight belt wear and this has started the same on the new but it only just rubs and the wear point is still on the neck part of the pump.
Am confident this will not cause any issues, the last managing some 35K kilometres without this causing trouble.
The other aspect was replacing the aluminium radiator.
Because I'd treated the system right in terms of correct-ish coolant the peripherals of the old radiator were reusable so I was lucky and only needed a core replacement.
Interestingly however, Race Radiators recommended ACDelco green and I'd been using a Nulon red but both of the same class of coolant. Time will tell on this I guess.
So the radiator repair rather than full replacement was about $500 cheaper but more importantly only a one month wait rather than 3 months to facilitate. Has meant I haven't missed out on the club's pending MotoGP track date in a couple of weeks.
So a bright and shiny look to Slowy's nose, along with straight fins .... for now!
Have learnt over the journey this set up needs multiple burping sessions to fetch out all the air. So far an initial static warm up, to check for leaks and burp plus a subsequent decent drive has seen another litre or so of coolant added and no leaks so all is well in the Low's garage.
If only the weather would turn a bit better and I'll do another drive and she'll be all great.
Cheers