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. To call any of these K4s streamlined would be quite mistaken, but we felt they were all special enough to stand out in unique deco schemes as well. To that end, we’ve applied a “what if” fantasy scheme based on other Pennsy practices to each of these variations.