Hi,
Ben's locos are all early version models and have .tga files, so when you are editing them go to the body folder and look for a tga file named for the main body of the loco. If they have lod functions there will be one file with either main or 1 in it's name, do this one first, save it then resize it to the same size as the next one down, which may be medium or 2 and save it with that name. do the same for a third one if there is one. It will likley take some experimenting to find out which parts are which at first but once you get used to the mapping set up it will become easier. Also to get ben's locos running in TS10 you will likley have to replace the engine config file and the sound file.
Cheers,
Bill69