Hi,
I've been reading the postings with interest for the last few days, as I'm the setter of the puzzle. However, I'd resisted posting anything so far as I had not seen a complete solution...until now.
The solution as detailed in Beer Monster's post is pretty much word perfect. I felt it only fair to interject here, to prevent people from wasting their time with other theories.
One thing which isn't clear from the posting is if all sides of the footpath signpost were searched. It should (hopefully) be clear from the clue which side to check, hence the comment about 'within a couple of inches'.
If all sides were checked, then I'm afraid it would appear that the gold has been found previously, and that the finder remained silent.
If not, then the gold is potentially still there.
Whichever way it is, congratulations are in order to all members of the 'team' on this board who contributed to finding the solution so quickly. I hope that you've enjoyed it & that the gold is still out there for someone to find.