Sage,
I do not know a magic way to manipulate the edge of the seam inwards. With something like this I select blocks of sand texture in squares then use the uniform scale, something like this:

- scale faces.jpg (217.78 KiB) Viewed 207 times
This way the edges of the seam, between first cut and fairway, move uniformly.
I don't know if this makes any sense, or if it makes you more confused

?
Let me know if this makes any sense, I will be away from my computer for the rest of the day, so I can answer your questions tomorrow.
Good luck
Ian