Bradford City Transport HKW82, a 1952 AEC Regent III with East Lancs bodywork. Very few operators bought Regent IIIs with concealed radiators, Bradford was one as were Devon General and Hull Corporation.
The design seen here was common to all and bears no resemblance to the later AEC version on the Regent V. Sheffield had one late batch of Mk III Regents with the standard AEC fronts in 1955/56. The bus is taking part in the Aire Valley running day.

Photo taken by Chris Hough, Sunday 14 October 2007, Otley bus station