I have designed a set of parts to convert a Model Power N gauge 4-4-0 steam loco into a HOn30 narrow gauge loco. This conversion is almost identical to the 2-6-0 version, here I will detail the differences. You can read the 2-6-0 instructions here - https://www.shapeways.com/forum/index.php?t=msg&th=16784 &start=0& The differences for the 4-4-0 are the cab position and tender-drawbar connection. The cab sits further forward on the boiler, up against the 'lump' arrowed. The handrails will need to be shortened when they are refitted. This means the tender is closer to the loco chassis than the 2-6-0. A new drawbar pin is needed. To do this, drill a hole in the front of the tender chassis, in the round mark as shown. Insert a piece of brass rod, long enough to engage in the drawbar. It can be secured with some glue when you are happy it's the correct length.