KR Models KRM-HUN-OO-S-79 KRM-HUN-OO-S-79 Hunslet Bo-Bo in British Steel Yellow/White "Big Keith" No.79 Diesel Locomotive - DCC Sound. The Scunthorpe Hunslet Bo-Bo. Work began on the 10 locomotives in 1972 and was completed by the end of 1973, numbered 70-79 (Works numbers 7281-7290) with one more joining them, number 80 (WN 7474) in 1977.