Paul has asked me to write to you.
You mentioned Peterborough Crescent as a closed station from the GN main line to the Northampton line but that station was a "Midland Railway" station and not on the line of route. I suggest that the next station instead of Castor should be Orton Waterville which was on a different site to the present Overton (formerly Ferry Meadows) station.
I am having difficulty in accessing the General Knowledge Quiz to check and confirm the answer to my question. The answer is that rugby and cricket could have been seen at all three grounds. Can you insert this answer on my behalf, please?