Mark,
I could visualize the tractor wheels being on the grass and the scraper on the gravel with no problems if there is no change in pitch between the gravel and the grass shoulder. If there is a change in pitch from the gravel to the shoulder, however, it seems that would put the scraper at a tilt and would require top 'n tilt (or at least tilt, either hydraulic or even manual adjustment on the length of the lift arm) to compensate for this change in pitch.
Is the grade of your gravel the same as the shoulder, or do they differ? What's your take on this if they are not in the same geometric plane (i.e. a grade/pitch change at the line of demarcation between gravel and grass)?
And Bob, are you still following all this discussion you just initiated? Any thoughts or feedback??