550 maranello optional modular wheels

Can anyone tell me if the optional factory wheels offered by Ferrari are Speedline or BBS for the 550 maranello? Are they the same for the 575 except for the rears being 19 inches? IS the offset of the factory modulars the same as the standard factory wheels?
How could you tell if a previous owner had changed them himself or got them from the factory if he does not have the window sticker anymore?
Thanks
Gary

Dont know, but thought they were BBS...and am looking for a set myself...there is a set for the 575 maranello on EBay but I dont know if they fit the 550