You only had 45days to open a dispute with eBay/Paypal. That has passed. So no help there.
This is a member to member Board. We can only offer advice and sympathy.
Did you use a tracked method of shipping to return the clock to the seller? This would have been necessary to win a Dispute.
But now that is by the by.
Go to the credit card you really paid with. Paypal is just a mediator. And boy do you need a mediator here. Call the 1-800 number for the card's customer service and ask about a chargeback.
Have all your dates, transaction numbers, payments and currency info handy for the clerk to process your refund.
But while cards have longer deadlines, they do have deadlines so act immediately.
In future, if you have a similar problem, do contact the seller , but keep the 45 day deadline in mind. EBay and PP will help, even to the extent of refunding you themselves and going after the seller for their money.
Phone your credit card.