How nice of you to share your machines. I know (hope) that the new owners will treasure them.
Probably not much to do with safety, but LABEL everything that is yours.
(I know that's a bit hard to do with pins and needles - I wonder if someone was obsessive if they could put a dab of nail polish on each one?)
A lot of people "talk with their hands" - don't have the rotary cutter in one of them while doing so.