i said coupe because i had about 30 tabs open and this one was the first marea tab, after several coupe tabs, so i assumed i was still in the coupe section.
multitasking is quicker, but from time to time you lose your place.
the bit about plastic casing is because yours are melted, but also because i thought your remove PCB was inside the key. checking the pic again i see you have meta style fobs instead.
generally speaking, every system is different, so even another fiat (or in this case meta) remote wont be helpful unless it is from the same system. in this case that is system1, shared by meta kits for the cinq bravo brava marea mk1punto, coupe, 145, 146, 155, mk1gtv, mk1spider and i'm sure there are more i'm forgetting.