I've just bought a new key cover with blank blade to replace my existing and rather beaten up one. Can I swap the blade and the electronics or do I have to get the blade cut to shape?

As far as I know you can swap everything though I only replaced the outer shell and the rubber buttons with only the Fiat logo looking a bit tired I'm sure someone will point you in the right direction of the right thread.

Here is a youtube video for key cover swap: