There's also this classic travelog of two railway fans gaijin-smashing their way through a closed route, although it's nearly two decades old: https://vienna-pyongyang.blogspot.com/
One of the best blog reads ever. Up there with the couple who drove through Congo.
Jaka Parker, from what I recall, was a diplomat in North Korea from Indonesia(?) which is why he was able to have greater access to Pyongyang (and beyond?). I don't think he's in North Korea anymore. Nonetheless, his videos are a great resource. And my guess is that tourism to NK in 2026 is from Russian citizens (and maybe Chinese citizens)?