I have a book with the detailed plans for Little Boy and Fat Man. More general descriptions of various fission and fusion designs have been published for decades. In fact, a child's science encyclopedia I had in the Sixties had a good general description of how the gun design works.

As has been repeatedly said, the only secret about the atom bomb is that it can be made.

I also remember that Analog article. Which I believe deliberately overstated some of the risks involved.