Rochester B bowl gasket mystery

[ACK]

I rebuilt my carb, an early to mid '60s Rochester B without an ID tag. It went smoothly, however, I came across one puzzling thing. The bowl gasket I pulled out didn't match what I received in the Quadrajet kit. I went to their website and the one that matches is for a '49 - '51 Rochester B (the left one).

The whole thing has me asking questions, like, is this just one of the many Rochester variants; did someone perform a rebuild with the incorrect bowl gasket; what if I just use the one that came with the rebuild kit; has any forum members been in the same situation?

I ordered the matching gasket, but I'm curious as to what would happen if I installed the newer one. I'm open to opinions, speculation, and past experiences.