"I live quite near Buckden. Where was the railway and the station - presumably the building's still there but a private house now?"
Unfortunately it has almost gone. If you follow the slip road from the A1 from Buckden and Brampton, the bridge under the A1 was the railway line route. That's why there is a kink on the A1 driving south into Buckden. The road utilises the railway bridge and had to be reinforced years ago to take the heavy A1 traffic. Another bridge, at the further end, since demolished, is the viewpoint of the photo I posted showing the station. The line headed off to the Offords, swinging around to Huntingdon. The Brampton tip has swallowed most of it.