If you have purchased any item on ebay which is "not as described", first of all, check the listing to see if there is anything you may have missed.  If the item which arrived is different to the listing, contact the seller to give them the option to respond.  If you are not happy with the response, open a "not as described" dispute.

If they are in the original packaging and have not been used then they are indeed classed as 'new' no matter how old they may be. If the state of the packaging was important to me and it is not shown in the listing I would ask before I bought. If an item is damaged without that being mentioned in the listing then open a not as described dispute as you would for any other item.

The items were plastic model Trains which deteriorate with age, they become very brittle, I did not realise they were so old until they started to fall apart with a little use, too late to do anything about it now.

This post is a general warning on buying "old stock"..