We still want to build an 8x8 (or maybe just 8x7) bit core memory one day to be able to store the word "coredump" as ASCII in it.
Some time ago we bought some cores on ebay and did setup a 2x2 matrix with them and played around a bit with using an oscilloscope and some FETs to write and read them.
The vendor, with whom I have absolutely no affiliation except for exchanging a few emails a several years ago, based his kits on a project that I did with a friend a long time ago .
It was a fun project that had interesting analog and digital sides to it.
I wonder how they assemble the cores and the wires efficiently, because that was always the most painful part when working with the cores.
(edit) a bit of digging around turned up an article  showing women building core memory for the Apollo Guidance Computer.
a thread from 2017: https://news.ycombinator.com/item?id=14485789
The article discusses wiring up your own 1-bit core memory within which you can store any bit you'd like. :)
In 1965 they introduced ferrite sheets, and a 1.18 MB memory card was 104 feet long.
1971 brought ferrite cores, and that same storage fit on a card under 9 feet long.