Hello lobo,

>One thing comes to mind but only as a "What I might try" thought not what they tried >thought.Make the passage dimensions high enough and place small diorite "rollers"
>(bored out and on metal rods) wedged along passage floor down until just short of
>area plug would cover.
--------------------------------------------------------------------------------------

You and I think alike only I was thinking of rollers under the stones in a hollowed out space keeping the plugs just barely above the floor. Of course if that were the case the rollers would still be there.

RLH