Maybe we have misread .
"All i can tell you is its from my mates land and that is where it is staying, archaeologists have allready tried to spirit it away and leave him with a plaster cast!!...and he is not having it!! "

The plaster cast /stookie may have been on the poor mates arm after archaeos tried wresting/spiriting the the "writing " away in a daring snatch and the mate ( term in Orkney for a friend ) has decided to to do without the stookie due to itchiness .