I've never sat down and tuned to Robert Johnston's guitar on his recordings but have always thought of him thinking and working out of G tuning.First string D then B G D G D .Thanks Dave T. I thuoght everyone eles played dust my broom out of D {E} but I always assumed RJ did it in G .I'll go listen alittle closer. Steve I've always liked learning from the inspiration of the performance of a master like Robert Johnson. There is so much to be gotten from the struggle of listening and playing.It's alot longer to get there but you learn so much more on the ride. Good luck with the tab..................Long live good slide playing...