It's surely one of those things that's very, very fussy to assemble but relatively easy to verify.

Someone built their own rope memory reader (https://www.youtube.com/watch?v=WquhaobDqLU) to access data stored in the Apollo modules.

Assembling core memory is a lot easier, there's a very simple pattern, and verifying that it works correctly isn't that hard either.

This is like weaving a complicated rug with many colors and a single-color rug.