I'm pretty sure they're absolutely stock and correct.
Those are early and use the 413 woofer, it had a smooth cone, and AFAIK most had a rolled cloth doped surround. Those look to have the thick painted aluminum dust caps that were used to add mass to the woofer cone to effectively extend it's response.
The later 411 woofer has a ribbed cone(looks very much like a JBL) foam surround, and 4 inch voice coil/motor.
Occasionally you'll see 413's trying to be passed as 411's, not much info out there on 411, and even less available for the 413 which usually raises a lotta ??????'s when they do show up.
I expect they'll go low considering the seller and shipping, a local interest might get a very good deal on em.
FWIW, they're in very nice shape for being born in march of '73, consecutive serial numbers which is rare, if they were local to me so i could see em in person first i'd probably not hesitate to throw 5 or 6 bills at em.:yes: