The LNER renumbered its locomotive stock during the period that these locomotives were being rebuilt, so some were renumbered at the time that they were rebuilt, some before rebuilding, and some after rebuilding. The renumbering plan for class B2 was the same as for class B17: in each case the first two digits were altered from 28 to 16. Thus 2803 became 1603 at rebuilding in October 1946; 2807 had already become 1607 (December 1946) prior to rebuilding in May 1947; and 2814 (rebuilt November 1946) became 1614 in December 1946. Between 1948 and 1950, British Railways increased these numbers by 60000; no. 61644 was so renumbered at the time of its rebuilding in March 1949.
