That seat is not correct for any year of Honda GoldWing.
Many folks offering seats for sale on eBay are misinformed and pass their lack of knowledge along to buyers. Unfortunately, you didn't know what you were buying and paid for their mistake. That's unfortunate. Depending on how this seat was listed and described, you could contact the seller and ask for a refund. However, if they stated 'no refunds', you're stuck with a seat. If this is the case, your best bet would be to pretty it up and post it on eBay. Simply state that you're unsure of the model year. Anyone looking for that particular seat will know what it is. For your information, below is a photo of a factory '78/'79 GoldWing seat. On the rear, the word 'Honda' is in gold. Here's
one currently for sale on eBay.