I thought I'd use them for the Time Machine but in the end they were simply too big and the wire between each one too short.
Last night I finally dug them out and had a go with the Adafruit library. This is fifty of them running a slightly faster version of their example code.
They work really nicely but again I suspect they'll be 'wrong' for my next project which needs to have a retro look. So much so that I suspect it'll be done with incandescent bulbs, relays and lots of messy point to point wiring as that's actually what it's supposed to look like.
Although these would make it really easy to make.