That's superb Bob, your spoons have just tied up all the known punches. There's an article in the Finial which sheds a bit more light on the chronological order of the marks. My spoon was suggested to be the first incarnation of the marks, yours tie up the 'S' with my marks. The article suggested the bird in flight mark may be last along with the sunburst as those punches appear to have been inherited by another maker who used those marks along with 'JH' at a later date.
Estelle Quick in her book 'A balance of Silver, the Story of the Silversmiths of Tain' could not find any evidence of the maker in Tain or surrounding areas. There was a new theory of the marks pointing towards Dumfries mentioned in the article but I've not found any more info since that article was published.
The article was by Colin T Fraser, FSA Scot.
Here's a link to the article: http://www.incorporationofgoldsmiths.org/content/media/The-Finial-Vol.-18-01-Sep-Oct-2007-Interesting-Family-of-Marks.pdf
Interesting stuff, I'm very happy to have found such an interesting spoon, it's my first Scottish provincial spoon.