At first blush, it didn't seem quite right, but on further reflection...
Really special pieces often get traded up the food chain by buyers with more information buying from sellers with less information. It feels sort of 'funny' that the person whose opinion you are buying is telling you that they are genuine but also wants to pay what seems
like an above-market price for them (but probably isn't).
If he has shared all the reasons why they are special (to him) and you are comfortable with the quick strike, then I suppose there is no issue.
Maybe the right answer is that he is only being asked if they are genuine or not, and beyond that, seller beware.
Whether you sell or hold, congratulations on the find. Apparently, you are