If it's considered genuine, and the seller seems to imply that it is...you know the end price is going to be 10-20X what the current price is, right?
Condition doesn't worry me, pieces at that leave were often not made to be mounted or used, they were high class even back then.
I haven't seen modern fakes of this sort of work, but that doesn't imply that they don't exist. Someone could ask the seller if they guarantee it would paper.