Should be a straight drop-in, THOUGH you will need to check the jumper to the right of the 74ls139 chip above the roms to be sure it is in the correct position (check documentation).
Then, as long as flipper and game ROMS are in proper slots (ROMS 14, 17, 20, or left to right, flipper 1, flipper 2, game rom, in bottom three sockets), you should be set to go.
Good luck!
Chris