Mortal Kombat II revisions?

[darkairplane]

Hello everyone, Im trying to decide on a purchase of a mortal kombat II board for my arcade but I have some concerns.  Seller claims the revision is 3.1 but the board has a memory expansion on it.  Wasn't 3.1 the final revision therefore it would've been on the updated 8mb t-unit?
Another question I have is that if 3.1 is the final revision should all roms be masked? and not have a little sticker on top? Thank you.  I want my cabinet to be as authentic as possible without any hacks on the board.

[darkairplane]

additional info:
Sale includes soundboard all cables and kick harness
Price:$240 this good? bad? fair? (cant seem to find any completes that are cheaper)

[Malenko]

you can run any version of MKII with the daughter card or not, it just meant burning bigger roms and removing that card. I upgraded from 2.0 to 3.1 to the latest 5.0XXXX Tourney hack and I still have the add on card. $240 sounds like a lot, check KLOV.