It has been done, chap on here and FF many moons ago showed it off. Think his user name was something like Stilodriver or similar but he'd done a tonne of stuff to his Schumacher including using a throttle body from a Maserati. The 147 interior he'd used was the tan/black leather option from a GTA, looked rather smart but don't know for sure how difficult it was to fit.

there was a bloke with a red stilo, might be talking about the same one with the 147 orange leather interior, couldnt tell aswell how hard was it tho... there was a video of him showing it off, red colour stilo if my memory tells me right...