the k1s were numbered 1630–1639 by the gnr, and became lner 4630-4639. the k2s were numbered 1640–1704 by the gnr, and became lner 4640-4704. in the lner's 1946 renumbering programme, the k2s were renumbered 1720–1794, and they later became british railways 61720–61794.