No. 5399 was the most mechanically successful of the poppet valve experiments, leading to their inclusion on the T1 Duplexes. Lima also took some liberties with a little streamlining on the running boards during her rebuild. Add in a front-end throttle cover and you’ve got a truly unique K4. 5399 received the usual front end pilot and smokebox changes in the mid-1940s and we’re offering both variations with appropriate period paint and lettering.