It is odd that it's certainly listed , and listed as out of stock, but there's no danger of selling it again as there is no Buy it Now.
If you have received notification that the buyer of the accepted offer has paid, then you should post the item, asap to the name and address eBay provided on the order details for you.
Should no label be available soon for you to print for this item , contact Customer Services.
I strongly recommend contacting CS 8 a.m. on a weekday when the lines open for ' live agents' as then, there's more chance of Dublin answering.
This is the easiest and quickest way to contact eBay Customer Services, for a Call Back option.
https://www.ebay.co.uk/help/eua?id=5190
Lines open 8 a.m. - 10 p.m. on weekdays
9 a.m. - 6 p.m. on weekends.
Automated agents will be available on chat outside of the above hours.
@bobzilla4tcg