That's the right MID for a 6x Made in Japan Panasonic BD-R. It's the same MID as the "cheap" 6x Panasonics. I don't think the archival grade discs are supposed to have a different MID, but I'm not certain.
In terms of how to tell it's legit, a disc quality scan after burning would be my first suggestion. This of course requires you to have a drive that can scan.