Inductive open core current limiter (Educational model)

For one if my master courses in Electrical Engineering, I needed to analyse the magnetic flux in an open-core current limiter*. Since I had problems understanding the physical events going on, I decided to sketch a model and print it so I could hold something in my hands to visualize everything better. Since its only for this purpose, I didnt print the bottom of the windings, but I included them if you would like to print them.

NOTE THAT THE MODEL IS 1:1 SCALE, I PRINTED IT AT 50%
Tolerances are at the high side, to make sure I could print it right from the first time (And I did!), so might be possible that the pieces can be rather loose.

*D. Cvoric et al. 3D nonlinear transient field-circuit modeling of inductive fault current limiters. 2015