Think these are nboots but want to confirm. They have SNK on the PCB but there are large Rom chips (look soldered on) on them which appear to be non-original. Took the pics with the shells still on but you should be able to still tell. Games play flawlessly. If you can't tell, I can post without shell, this was just more time consuming.
http://i544.photobucket.com/albums/hh335/boss0033/NeoGames003.jpg
http://i544.photobucket.com/albums/hh335/boss0033/NeoGames002.jpg
http://i544.photobucket.com/albums/hh335/boss0033/NeoGames003.jpg
http://i544.photobucket.com/albums/hh335/boss0033/NeoGames002.jpg