When I sold my wheels I sent pictures of my M5 and the rear of the wheels with the made in Germany stamp, etc. You should also use Paypal in the event they are fake you can file a dispute. Tires are usually Michelin I've never seen Bridgestone unless he replaced them but then he must have put a lot of miles on the wheels and OEM tires.
Current ///M: '13 F10 M5, Sapphire Black, Eisenmann Race Exhaust, CF Delete, H&R Sport Springs, iND Cosmetics, Escort 9500ix hardwired, 21" Vorsteiner VFF-103 w/Michelin PSS, RKP Front Lip, Challenge Rear Diffuser, M Illuminated Door Projectors, and LCI M Performance Black Grills
'15 i3 BEV