Zfilm alteration equation coming up.
The station# that is PositionA along JFK's path = 280.3 (inside blue box)
The location of the initial data input for CE884 = Station# 329.2 (blue arrow)
That difference in distance = 48.9ft.
This equals the same distance from CE884 extant z255-z313. (Apples to Apples)
The elevation difference is almost the same, a difference of .01ft x 18.3ft = .183ft = 2.196 inches