Thanks to all,
As always, from many special "Forum-contributors", I am now beleagured/inundated with useful information and associated tips-'n-trix, for which I can only thank you, as I continue my apprenticeship 😉 🙂
Now the car is SORN'd - I can get to this issue - and move on with the A/C project and heater matrix revival.
All I need is some dry weather, a following wind, some bolt-loosening-shrinking sparkles, a version of the infinite-improbability-ancilliary-remover, good luck, replacement knuckles etc. etc. Oh!, and suitable working replacement part(s). (I already have way more expletives than is good for one person ... )
On a slightly more practical note - where is the best place to get the pump refurbished, or are there any newer/aftermarket replacements ? and what about gaskets?
As always - TIA