I think you are right John, from the timetable it looks as though Sir Nigel is in Ferme Park sidings (the lines closest to Cranford Way) which means we get to see it heading down to Kings Cross c. 08.54 before its return pass at 09.39.
Thanks for posting this Liz - this is a great engine named in honour of a great man.
Movie in the pouring rain of Sir Nigel Gresley moving slowly north past Hornsey station at about 8:55 this morning, here. Sorry about the quality, finger on lens etc.