If I was to speculate based on the claims of the 1893 news paper story. The newest coins was 60 years old therefore the cache was some connected to the Civil war? Perhaps a family cache of money hidden in the that time of conflict? The owner either died of old age or died in the civil war.
Using where there smoke there fire principle perhaps money was also hidden in the original farm house. Maybe there was other owners before the Owens family became owners? In the above ground shot it appears to be traces seen from above of the location of the original farmhouse drawn in red below. Perhaps another place to swing a detector also?
So this is why these stories are little gems because you never know where there stories can take you?