Does anyone know why the seat tube of this Robinson frame looks so strange ? I have never seen one of these before, so i don't know if it's normal or if it has been repaired, as i would say. Thanks in advance !!

That's just how they came.

It's just a decorative plate they welded on to it. My 1988 Robinson cruiser has the same thing.

the plates are on the USA built frames.

Thank you guys !! This one is for sale on eBay for a few bucks (i think 40$), 1 day left and no bidder. Unfortunatly (for me) USA bidders only... may be gonna contact the seller in case where he would want to sell it. i am not really interested in it but it's not expensive...

I have a '94 frame with exactly the same plate. It's genuine.