What removes rattlecan clear coat without damaging plastic?

I have some old 40k plastic models that I painted many years ago, and sealed with rattlecan clear coat. I don't remember the brand, but likely Krylon.

Every suggestion I can find recommends ISO - I have had these models in 99% ISO for several days and the clear has not budged. The ISO is almost perfectly clean. There is acrylic paint underneath the clear that ultimately needs to be removed, but the clear is doing its job very well to protect the paint!

I have also gone at the models quite aggressively with a toothbrush, but have only managed to get a slight bit of color transfer on the brush. Any other suggestions? Thanks