Hi Steve,
I've rebuilt Beta ignitions which are probably similar, and in these it's the plastic which finally goes brittle from heat fatigue.
I spent a lot of time creating a an AutoCAD sold model of the one plastic bit, and was about to have it 'built' by one of those rapid-protyping services (quite costly) then decided to us QBond cyanoacrylate glue and (black) powder to repair it.
Stripping it is fiddly (drilling out rivets & push pins, cutting off wires, losing minute springs
etc.) then shaping it post repair with needle files - I'm mad, I know!
I'd suggest you rather check Eper for a Panda or such-like equivalent to buy new from your Fiat dealer.
Regards,