How to get level 6 military stealth boots without cheating?

[Blasphemous]

As in the title, how do I get the boots without creative menu?

Since max craftable level is obviously 5 and the boots do not seem to spawn randomly or via trader quest rewards, what other ways are there of getting them?

I think I've had a sufficiently large sample of random drops across multiple games in recent memory, around 2k hours to be exact, and I have seen the regular boots many times  already but never the stealth version. Is this a devs' oversight?