@ tubby linton
The graphic on page 3 of the other thread was originally put together in September last, and when looking at it in the light of the FDR data, the FP is somewhat in error. As someone has already pointed out to me in a PM, I probably transposed 1380 for 1830 when plotting the alt at IMTOY.
I'm currently having a look at the FDR .csv data file and extracting the relevant data to update the graphic.