The original disc has five layers of canvas-like material. On both sides of the centre layer thin sections of spring steel give the disc its required strength for the way it is applied on Fulvia's (and Flavia's). On the original discs these steel sections have rusted away. The canvas then quickly tears.
Replacement discs that I have seen so far do NOT have the steel sections. They are utterly dangerous as shown on the picture below. As you can see from the grease and dirt around the disc, the disc was put in recently and has torn already.

I have the thin spring steel (stainless steel variety) and I am ready to laser cut the sections. However, I cannot find a suitable canvas like material of 1,5 mm thick. It should either be impregnated canvas, natural or synthetic, or fibre reinforced rubber which can be either laser cut or water cut.
I someone can help, let me know.