Odd discoloration on "brand new" head drum
 

Hello everyone,
I recently grabbed a supposedly brand new Sony Hi8 head drum off of ebay for 25 pounds. Received the unit today and all looks well except some slight darkening around the head chips (photo bellow). I've only ever seen this on drums that have been used, so I don't know if it's normal for it to appear on a new one. Have I been scammed?
In any case it was only 25 quid and it's always nice to have replacements, so I won't be too upset if it's not actually brand new. I don't plan to swap it into a camera right now as I want to record a trip on a Hi8 model in the summer and wanted a new head for that, so I'll find out if it has reduced comet tails around the date and time display when I take the camera apart and replace the current one in June.
Thanks,
HBB