Sega Cart variation (NOT label) Streets of Rage 2

[y9784]

In my thrifting journey today, I picked up a cart for Rolling Thunder 3 and Streets of Rage 2. After getting both home, cleaning them, and opening up them to clean the pins, I noticed the Streets cart had a weird shape to the top of back half for the cart. I have included shots of this variant with this post.

At first, I thought the back half had been melted, but upon opening, I noticed a plastic piece juts out from that part of the cart as if it would fit into its complement on the front half (there is no corresponding shape on the front piece). This weird plastic shape is not present on any of my other Sega Genesis carts. I always clean all my games and open them up when I get them.

Has anyone seen this before?

[PreZZ]

maybe it just melt with heat?

[theclaw]

Someone could've replaced the back piece.

I can't think of much weird about that game itself. Other than maybe the region lock. US version didn't really cut Japan text, just hid it behind an error message.

[y9784]

I don't have any other Genesis cart with a tab on the top of the back half of the cart. Nothing else seems odd about the cart. All the writing and SEGA logo is there on the back.

[Nz17]

You might try asking the SEGA experts over at SEGA-16 for some advice as that crew is completely bonkers for 16-bit SEGA consoles and they should definitely know. If you find an answer, please post it here so the rest of us can know! Thanks.

[BlastProcessing402]

To be honest, just looks like some sort of molding defect.