Found this hunting down famicom converters. It felt heavier than the other black labels so I picked it up. No converter, but...



Sorry for the big pic, but it shows the chips better.

The EPROM is hand soldered, the CHR ROM is machine soldered. I've tested it and it plays just like any other version of the game except that the "gang" mode is impossible. You can't shoot the second bandit that comes out from the saloon doors.

Any clues? I just got my Willem in the mail, so I might pull the chip and dump it.

It's most likely an eprom added to the cart after a factory repair:



These are a few I've pulled from retail carts over the years, though I've got maybe 3-4 more. Very cool info about it being impossible to complete, though it's likely an error and not a feature in the game. Cool piece regardless.

Since the repaired prg chip is a eeprom and not a maskrom, it can be bitrot, correct?

Hmm, very interesting. Gonna start checking through my carts.