Possible Pirate/Wrong Cartridge for Megamania

[CartoonCade]

So, for whatever reason, I recently bought Megamania for Atari 2600 at a local game store. The label was worn down, the screw holes were open (with screws still inside), and the game looked dirty. After some fiddling, I managed to get it working. The only problem? Kaboom! Was displaying on my TV. After opening the cartridge, I found two different serial numbers on the casing, and what I assume to be the Kaboom! ROM chip. I don't know why this happened. I'm not sure if this was intentional, or if someone did this on purpose, but I own a copy of Megamania that plays Kaboom! Instead. I've included some pictures, and any help as to clarifying what the heck is going on is welcome. I'm not an idiot, and I likely just bought a messed up game that someone put together, or that someone just put the wrong ROM in the wrong case. I just wanna know what is going on and what I should do?

 

TL;DR - My copy of Megamania is actually Kaboom! And I don't know why.

 

NOTES:

 

ROM CHIP SERIAL NO.:

AG-910-00A (©1981 ACTIVISION)

 

CARTRIDGE SERIAL NOS.:

TOP CASE (WITH LABEL) - AG-920-01E

PTM-6D

BOTTOM CASE - AG-920-02E PTM-7D

[toiletunes]

I'm guessing someone had a dead Megamania with an intact shell and a working Kaboom! with a busted shell, and cobbled this together.

[CartoonCade]

I was just very taken by surprise. I've never had an Atari game be the wrong one before but I guess it happens just like any other system.

[chas10e]

I just wanna know what is going on and what I should do?

 

if you have some jitter free paddles, play Kaboom!

 

you should beable to bring it to the attention of the store owner & perhaps get another Megamania hopefully keeping the Kaboom before he just tosses it in the trash

[CartoonCade]

No matter how jitter free my paddles are, Kaboom! Is the one exception I'll probably just keep the cart. It was only $6, so I'm not too terribly upset. I already have a functioning cartridge of Kaboom!, So I'll just keep this around as an oddity. Thank you for your help, though! This is the weirdest cart I have, aside from Journey Escape.

[Zonie]

Rarity 11