Recently moved to the area and have been busy trying to record this line before work gets fully under way
http://cliffjones.zenfolio.com/bletchley_bicester shows parts of the disused line between Bletchley and Bicester (work-in-progress, gallery not yet complete)
http://cliffjones.zenfolio.com/bicesterlink features the section between Bicester Town and Oxford around the date of the recent closure to passenger traffic
Thanks for looking!