are aprillia sr 125 engine same as a piaggio rolling nut 125?

are aprillia sr 125 engine same as rolling nut piaggio engine ? if so would it bolt straight in and run? are any other scooters running same rolling nut engine that will bolt straight in ? and if so are they piaggio made even tho aprillia or other badge? this is prob common knowledge but like i said before just doin my research to update mine and am new to belt driven shit

 

oh and i want air cooled not water cooled and could do with knowing if there are any differences to the piaggio rolling nut engines fitted to by different manufacturers, cheers