It's funny, I was just reading up on pewter spoon designs a few days back. I found this great pdf guide for 17th and 18th century varieties and although there aren't any exact matches one type might be worth narrowing the search to:
It's described as a "farmer George" as in KGIII and the heart under the portrait caught my eye. Perhaps your particular spoon maker left out the difficult to design bust and shortened the design to the crown over the heart?
That is what I was think DC. This is probably a farm carved mold. Many talented persons carved molds and melted and repaired their pewter spoons to keep them fresh. That is what this looks like to me.