If I understand correctly, your point coordinates are "correct" for some coordinate reference system slightly different from State Plane Meters, like there is an offset of 30m or so (as I've mapped above). The offset value in your spreadsheet corresponds to the offset from the road center, where zero would be the center of the road. Unfortunately, as they are, the coordinates don't correspond to the road in terms of regular State Plane Meters. Does your survey plan give any other hints about the coordinate reference system?