The idea that North Korean industry is just it's military is a western myth. Most things industrial North Korea is ahead of Vietnam. Vietnam is a third world country, North Korea is not.Yes but only in MIC. Their civil industry is not cost competitive. That doesn't mean its behind, but the reality is, mass produced handmade shirts sold for 50 cents made by sweatshop laborers will make more money than a power plant or engine that's a few decades out of date, even though its much easier to sew shirts than build power stations or engines.
It's the same problem Ukraine faced, actually - they had all this industry, including jet engines, yet can't sell them because they're just a little worse than the competition, but in a market with so few buyers, a little worse might as well be stone age.
The problems North Korea have nothing in common with Ukraine whatsoever. The Ukrainians mismanaged the assets they had inherited from the USSR through corruption, despite receiving billions from both the EU and Russia. North Koreans have had to build everything from scratch from nothing.