How can you tell.......


Dear APC SP11 and SP9 users,
How can you tell it is a real MK2 or only an upgrade from MK1? Someone told me the upgrade is with a metal sticker next to "SP11", and a real MK2 is with a stamp "MKII", is it true? If so, how come in the database of ARC "www.arcbd.ws", the MKII is with a metal sticker?
One more, about the SP9, is the one with stamp "MKII" a real MK2? I have seen one without a stamp but really print it as "SP9MKII", does it mean the stamped one is an upgrade this time? I'm a bit confused now!
eugeneli