I recently did the Cholsey & Wallingford Railway (recently being yesterday in this case) and it was a really nice little line. Very short, maybe 3 miles, but certainly unusual in having a crossing of the A4130 just after leaving Wallingford.
Definitely recommend the line to anyone interested in going, it was only £5 for a day pass yesterday and I’d have spent more time on the railway, if it weren’t for needing to ride back up towards Radley. Which turned into a ride up to Oxford instead but that’s a whole other story!
Second heritage railway completed for track in a week, no idea which one is next but I’d not be surprised if it’s the line out of Chinnor. I need to research that one a bit more yet.