Swiss custom do not care about Hermes Cites.
If the seller is US resident and bought this item in the US, it is normal that they did not get a Cites.
Cites is a "travel ticket" not a "passport". Each time you move a Croc Item from a country to another AND from an owner to another, you need a Cites. The Cites is valid for ONE travel /transfer of ownership.
Cites is NOT a certificate of origin of the skins. It is a tracking document for the skins that are internationally traded.
Swiss customs are very well aware of this , and among all customs I ever had to deal with they are the most knowlegeable and fair.
What they are asking for is a Cites permit of re-exportation issued by Cites USA ( Fish & Wildlife? ) stating the name & address of the sender ( your seller) and the name & address of receipient, the scientific name of skins and registration number of initial importation in the USA.
This permit is valid only for this transaction , and only for 6 months.
It was the duty of your seller to ask for this permit and attach it to the shipment.
Your seller could try to get one now and then you will provide it to Swiss Customs.
If they do not know the registration number they simply fill it as "unknown"...
And then only your shipment will be released. There is nothing to pay besides normal VAT, but you have to do this.
It is of no use to say that Hermes does not give original Cites because this is not what they are asking for. YKWIM....
Now you could call them and ask them if they would accept a Cites Permit of importation issued by BERN. If yes, you will have to ask it . It could take one to four weeks but it will work just fine and you will be sure to be in control of the situation.
PM me if you need more help, I will be here for you.