With this question, posed to the UDIC Facebook group, U3.5: Pax Britannia was born. Initially nameless, briefly known as Ultima 3.5 before the registered trademark of Electronic Arts was dropped from the title, and subsequently sub-titled Pax Britannia, this is where it all started:
https://www.facebook.com/groups/UltimaDragons/permalink/10150508826738797/
Well, except for that earlier incarnation as ZXU4 for the Chloe 280SE, but that’s a story for another day.