Linked list modelling kits

Do such things exist? Just want something for my students.

I made a bunch of data structure animations in Logo and Turbo Pascal long ago. A little stick figure would move a box off the stack when you hit the POP button, or laboriously do all the steps of (+ 2 3) like a warehouse grunt. I sold it to IBM who, at the time, were training their blue collar workers to program rather than lay them off. It was a big hit, with the added bonus of being written in a beginner's language.

I have no idea where the discs are now, though. A programming teacher like yourself shouldn't have any trouble making your own. Logo is all about that kind of graphics.