The last of the clean-up.
Gateway, like Fern Glen, was produced by the USGS after the 1975, so had the correct boundary. So I removed the black center line, CO, and boundary words. Repaired the dark blue river edge, contours, river water (still doesnt lay down as nicely as I would wish), and the south bank boundary line. Then added + along the Park boundary.
Vulcans T is an old, old map, and has a stippled boundary on the north bank from the days of the second Monument. However, removing this using the Selective Brush (A) followed by Enhance0->adjust color->replace color (with new color background set by light =100%) was a snap for the red and pink. The browns that were left matched the land contours, and so only a little clean-up was needed. Then the pencil & magic eraser for the center line and CO. There was a black boundary on the north side, which had to come out, and "indian" was wrongly placed. "Reservation Boundary" was ok; the only time. Then the water edge and river water needed to be repaired.
So unless I have missed something, the new south shore/river edge boundary is the major thing that needs adding, along with appropriate labels. A stippled land boundary for the Park is required on two maps.