I believe L-3 is the most up-to-date version. Since Williams didn’t keep change logs, there’s no way to tell what’s been fixed from revision 1, 2, or 3. It could be something as simple as a translation issue fixed for other languages, or coinage things. Or it could be as complex as a major software bug fix.

Action Pinball is a good resource for ROMs.

There are two other “specialty” ROMs out there too: the family roms which omits the word “bitchen” from the game, and pinsider Soren’s tournament ROM, that equalizes the jackpot between players, and eliminates the “shoot the center ramp until you win” strategy.

Did you burn it yourself or find someone to do it for you? I’d like to get a copy for myself sometime, but I don’t have the means to burn my own ROMs.