A fellow skinner and I have found a major glitch w/ Plane textures and Multiplayer. If you simply add a new texture to the original file and edit the cfg file to show said texture other people that have the same texture but different  fltsim.# in their cfg file. Will not be able to see the texture you worked long and hard on. What we have been doing is make stand alone files of the original files and adding the new texture to that. If you go to http://downloads.fs-mp.com/propplanes.html download the FSMP Flight School Planes, install them then go to your SimObjects there will be a new files called “FSMP_FlightSchool_C172” and “FSMP_FlightSchool_beech_baron_58”. Have a look at these and you will see what we are doing for a work around for the MP glitch.