Thank you, Charlie, for the information about the loco. Looks like you also see it as a possible Martin Lewis Northern.
I'm still not sure if the dimensions match the Martin Lewis loco, but if I can find the drawings and instruction booklet I can probably make things work regardless.
Still looking for the 1/4" scale drawings and instruction booklet for the Martin Lewis Little Engines Northern (and the current Little Engines catalogue does not offer it). If anyone has a line on one, please let me know.