Savage Reich Star 01.0: Initial Inspiration Notes

I recently finished watching the first season of The Man in the High Castle, and it got me thinking. It made a point to portray the disparity in technology between the Nippon Empire and the Reich. For example, the Reich had super sonic jets while Japan still relied on steamships to cross the oceans. Now this aspect may be Hollywood taking historical liberties but I do seem to remember that Japan was somewhat behind the times in certain aspects of the war.
One inaccuracy though was that the Japanese did not have jet fighters before the end of the war. They in fact did, as part of their agreement with the Nazis, build a prototype. https://en.wikipedia.org/wiki/Nakajima_Kikka
Another very interesting aspect of the show is balance of power, perhaps because of the disparity of technology. The Nazis obtained a atom bomb and did not share with the Japanese. This has left the Reich as the dominant superpower. The show basically ends up being about how the Nippon Empire gets the upperhand on this struggle while the Germans try to goad the Japs into War through subterfuge.
I suppose, from a Reich Star perspective, this would be a turning point event. Up until the end of the show, I was having a hard time imaging that world 175+ years into the future – the central premise of Reich Star. It’s hard to see, at least in that situation, both the Empire and the Reich lasting that long. But I suppose certain key events have to happen to maintain the cold war between them, like both obtaining nuclear tech, to make it last that long.
Space travel is a big event as well, I would think. Once the Reich landed on the moon (1959 in the Reich Star timeline), the space races advanced both factions tech. I would imagine considerable competition to colonize the solar system would then start, while each side raced to develop interstellar travel technology.
Another question: how did the resistance last so long? Of course, there will always be people who will fight back against oppression. But for 200 years, will they always have the resources to conduct their fight? Or will the resistance have its ebbs and flows? Cyclical? The Axis will get an edge on them for a while but eventually they will find a new energy somewhere, somehow.
I think a more realistic and cyclical approach to the setting may give me a better perspective, because most of the conversion is going to be setting stuff. The Science Fiction Companion for Savage Worlds will contain most of the tech we are going to need. The only things I am going to need are Edges and Traits, Archetypes, and setting information (which is extensive).
I want to maintain as much of the original setting as possible but add enough realism and respect for history as one can logically inject without making it unplayable.