I've looked through the variants but can't find the exhibition and dig rules you used. Any idea which posts they were in?
I don't know how to do the fancy here's the thread reference Greg because I'm still semi-BGG illiterate but if you go to "Reducing Luck Through Reducing Draws" you will see that the OP suggests some variations which I have in fact misunderstood !
Anyway , the leaving out 1 sand for each dig on the board near the dig site worked well again tonight when I played my daughter . We ended up with between 3-5 sand at each site by game's end which obviously increases(not unreasonably , I'd have thought)the opportunity of grabbing artifacts near game's end . In fact in very late , modest digs both my daughter and I got reasonable returns for our time .
The Exhibition variant used is proposed by Michael Stanley in the post "Exhibition Variant".
Again tonight we used the exhibitions - not extensively but they seemed to provide another viable avenue to score .
Hope that helps Greg !!