Modern Vespa

I've bought one 1976 super recently.
My friend told me that there's a round mark on the side which shows the frame is genuine, but I couldn't find the mark on mine.
Should I believe in this theory? Or it's just a rumor?

I'm assuming that pic is your friend's bike? wtf is with the weld on the frame tunnel? Kinda suspicious for a frankenbodge job. Perhaps a legit reason for it - but I woulda thought tiger territory issue right there - looks like a great place for a bike to fold under pressure. I'd be more worried about that than a missing circle.

But don't know the answer to your actual question sorry.

Hi
I don' t know this theory
But look châssis number for see in the vespa listing

My VBC's are legit and both have stamped circles there but I kinda doubt it means anything. I'd be more concerned about those welds.

Thanks for the reply!
The photo was taken in a workshop, so I don't know too much about that chassis .